The URL can be used to link to this page

Home My WebLink AboutAPA1761United States Office of Air Quality EPA-450/4-80-031 Environmental Protection Planning and Standards November 1980 Agency Research Triangle Park NC 27711 Air .=o EPA Workbook for Estimating Visibility Impairment EPA-480/4-80-031 Workbook for Estimating Visibility Impairment by Douglas A. Latimer and Robert G. Ireson Systems Applications, Inc. 950 Northgate Drive San Rafael, California 94903 Contract No. 68-02=0337 Prepared for U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Air, Noise, and Radiation Office of Air Quality Planning and Standards Research Triangle Park, North Carolina 27711 November 1980 This report is issued by the Environmental Protection Agency to report technical data of interest to a limited number of readers. Copies are available - in limited quantities - from the Library Services Office (MD-35) , U.S. Environmental Protection Agency, Research Triangl! Park, North Carolina 27711; or, for a fee, from the National Technical Infor- mation Service, 5285 Port Royal Road, Springfield, Virginia 22161, Publication No. EPA-450/4-80-031 ii Preface This workbook provides screening techniques for assessing visibility Impairment from a single emissions source. EPA believes these techniques are at a point where the results should now be employed to assist decision - makers in their assessments. The approach is through a hierarchy of three levels of analysis, somewhat analogous to that in EPA's "Guideline for A1r Quality Maintenance P1anni*ng and Analysis Volume 10 (Revised): Procedures for Evaluating the Air Quality Impact of New Stationary Sources," EPA-450/4-79-001. Frequent consultation between users and decision -makers is encouraged so that difficulties, misapplications or unjustified interpretations can be avoided. One option in the level-2 analysis and the level-3 analysis are based on the Plume Visibility Model (PLUVUE) and examples/applications are provided based on output from this model. EPA has also published the "User's Manual for the Plume Visibility Model (PLUVUE),"EPA-450/4- 80-02. However, the Agency has not yet recommended any visibility model for routine use in regulatory applications. iii ACKNOWLEDGMENTS The guidance, helpful comments, and the idea for the screening analyses approach contributed by the EPA Project Officers, Steven Eigsti and James Dicke, are much appreciated. William Malm of the EPA's Environ- mental Monitoring and Support Laboratory at Las Vegas deserves thanks for his suggestions regarding the use of contrast and contrast reduction as the basis for this workbook. The efforts of the authors of the workbook, Douglas A. Latimer and . Robert G. Ireson, under Contract No. 68-02-3337 with Systems Applications, Inc., San Rafael, California, are gratefully acknowledged. Also at SAI, Robert Bergstrom and Thomas Ackerman provided the computations based on Mie scattering theory, which are the basis of many of the tables and figures in this report, while Hoi-Ying Holman and Clark Johnson exercised the visibility computer model for the reference tables and figures provided in the appendix. iv CONTENTS Figures.............................................................. vi Tables............................................................... x Nomenclature......................................................... xiii 1 INTRODUCTION ............................................... 1 1.1 Classes of Visibility Impairment ........................... 2 1.2 Approach Used in This Workbook ............................. 4 2 GENERAL CONCEPTS ........................................... 7 2.1 Physical Concepts Related to Visibility Impairment......... 7 2.1.1 Visual Perception .......................................... 7 2.1.2 Fundamental Causes of Visibility Impairment ................ 8 2.1.3 Atmospheric Optics ......................................... 11 2.1.4 Plume Visual Impacts ....................................... 16 2.1.5 Characterizing Visibility Impairment ....................... 19 2.2 Plume -Observer Geometry .................................... 21 2.3 Characterizing the Frequency Distribution of Plume 2.3.1 Visibility Impacts ......................................... Wind Speed.: .... 000 ... 0 ... 0 ... 0 .... ***-0* ... 0 ... 35 39 2.3.2 Wind Direction ............................................. 39 2.3.3 Atmospheric Stability ...................................... 43 2.3.4 Background Ozone_Concentration ............................. 44 2.3.5 Background Visual Range .................................... 44 2.3.6 Study Area Topography ...................................... 45 2.3.7 Season and Time of Day ..................................... 45 2.3.8 Model Runs ................................................. 45 3 LEVEL-1 VISIBILITY SCREENING ANALYSIS ...................... 47 3.1 3.1.1 3.1.2 Derivation of Level-1 Screening Analysis ................... Impacts of Particulate and NOx Emissions ................... Impacts of S02 Emissions ................................... 47 50 53 3.2 Instructions for Level-1 Screening Analysis ................ 56 3.3 Example Applications of the Level-1 Analysis ............... 61 3.3.1 3.3.2 Example 1.................................................. Ex4mple 2................P.................................. 61 63 v 4 LEVEL-2 VISIBILITY SCREENING ANALYSIS ...................... 65 4.1 Identification of Worst -Case Conditions .................... 65 4.1.1 Location of Emissions Source and Class I Area(s)........... 66 4.1.2 Meteorological Conditions .................................. 68 4.1.3 Background Ozone Concentration ............................. 89 4.1.4 Background Visual Range .................................... 91 4.2 Hand Calculation of Worst -Case Visual Impacts .............. 92 4.2.1 Determining the Geometry of Plume, Observer, Viewing Background, and Sun...............................0...0.... 93 4.2.2 Calculating Plume Optical*Depth ............................ 99 4.2.3 Calculating Phase Functions ................................ 111 4.2.4 Calculating Plume Contrast and Contrast Reduction.......... 117 4.3 Use of Reference Tables for NO2 Impacts.. ................... 119 4.4 Use of Reference Figures for Power Plants .................. 121 4.5 Use of the Computer Model .................................. 121 4.6 Example Calculations ....................................... 121 4.7 Summary of Level-1 and Level-2 Procedures .................. 122 5 SUGGESTIONS FOR DETAILED VISIBILITY IMPACT ANALYSES (LEVEL-3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 5.1 Frequency of Occurrence of Impact .......................... 132 5.2 Appearance of Impacts ...................................... 133 5.3 Impacts on Scenic Beauty ......... .....:.... ................ 141 5.4 Impacts of Existing Emissions Sources ...................... 143 5.5 Regional Impacts ........................................... .144 APPENDIXES A CHARACTERIZING GENERAL HAZE ................................ 147 A.1 Wavelength Dependence ...................................... 147 A.2 The Contrast Formula ....................................... 148 A.3 Quantifying Increases in Atmospheric Haze .................. 149 A.3.1 Plume Impacts .............................................. 150 A.3.2 Regional Haze Impacts ...................................... 153 A.4 The Effect of Increased Haze on the Contrast of LandscapeFeatures...................................0.0... 153 A.5 Summary .................................................... 156 B PHASE FUNCTIONS ............................................ 161 C PLUME DISCOLORATION PARAMETERS FOR VARIOUS NO2 LINE - OF -SIGHT INTEGRALS AND BACKGROUND CONDITIONS ............... 189 D REFERENCE FIGURES AND TABLES FOR POWER PLANT VISUAL IMPACTS ............................................. 241 vi E TWO EXAMPLE APPLICATIONS OF THE LEVEL-1 AND LEVEL-2 ANALYSES ........................................... 323 E.1 Example 1--Coal-Fired Power Plant .......................... 323 E.1.1 Level-1 Analysis ........................................... 323 E.1.2 Level-2 Analysis ........................................... 326 E.1.3 Calculation of Plume Optical Depth ......................... 342 E.1.4 Phase Function Calculations ................................ 348 E.1.5 Calculating Plume Contrasts ................................ 352 E.1.6 Calculating Reduction in Sky/Terrain Contrast Causedby Plume ............................................ 355 E.1.7 General Haze Effects ....................................... 356 E.1.8 Comparison of Results with Reference Tables ................ 357 E.2 Example 2--Cement Plant and Related Operations ............. 359 E.2.1 Level-1 Analysis ........................................... 359 E.2.2 Level-2 Analysis ........................................... 362 REFERENCES........................................................... 371 vii 1 N Cl L 2 FIGURES Schematic of Visibility Screening Analysis Procedure.......... 5 Effect of an Atmosphere on the Perceived Light Intensity ofObjects .................................................... 13 Object -Observer Geometry with Plume ........................... 17 Five Basic Situations in Which Air Pollution is Visually Perceptible .......................................... 20 Plan View of Observer -Plume Geometry .......................... 28 Elevation View of -Observer -Plume Geometry ..................... 29 7 Plan View of Four Possible Plume Parcel Trajectories That Would Transport Emissions from a Source to Affect a Vista in a Class I Area ..................................... 34 9 10 11 12 13 14 Example of a Frequency Distribution of Visual Impact.......... 37 Schematic Diagram Showing Plume -Observer Geometry for Two Wind Directions..... ........................................... 41 Two Types of Plume Visibility Impairment Considered in the Level-1 Visibility Screening Analysis ..................... 48 Geometry of Plume, Observer, and Line of Sight Used in Level-1 Visibility Screening Analysis ......................... 48 Vertical Dispersion Coefficient (az) as a Function of Downwind Distance from the Source ............................. 57 Regional Backqround Visual Range Values (rv0) for Use in Level-1 Visibility Screening Analysis ......................... 59 Example of Map Showing Emissions Source, Class I Areas, and Stable Plume Trajectories ................................. 69 Viii 15 Examples of Terrain Elevation Plots ........................... 70 16 Joint Frequency Distribution Tables Required to Esti- mate Worst -Case Meteorological Conditions for Plume Discoloration................................................. 75 17 Schematic Diagram Showing Emissions Source, Observer Locations, and Wind Direction Sectors .....................0... 77 18 Joint Frequency Distribution Tables Required to Estimate Worst -Case Meteorological Conditions for Visibility Impairment Due to S02 Emissions ............................... 83 19 Example Map Showing Class I Areas in Region Around Emissions Source and Wind Direction/Speed Sectors ............. 86 20 A Schematic of the Vertical 03 Structure and Its Diurnal and Seasonal Variations at Remote Sites ........................ 90 21 Locus of Plume Centerlines within Worst -Case Wind DirectionSector .............................................. 94 22 Observer -Plume Orientation for Level-2 Visibility ScreeningAnalysis ............................................ 96 23 Plan View of Assumed Plume -Observer Geometry for Level-2 Visibility Screening Calculations ............................. 93 24 Scattering -to -Volume Ratios for Various Size Distributions................................................. 101 25 Wavelength Dependence of Light Absorption of Nitrogen Dioxide....................................................... 108 26 Phase Functions for Various Particle Size Distributions................................................. 113 27 Logic Flow Diagram for Level-1 Analysis ....................... 123 28 Logic Flow Diagram for Level-2 Analysis ....................... 124 29 Examples of Predicted Frequency of Occurrence of Plume Discoloration Perceptible from a Class I Area: Number of Mornings in the Designated Season with an Impact Greater than the Indicated Value .............................. 134 ix 30 Examples of Predicted Frequency of Occurrence of Haze (Visual Range Reduction) in a Class I Area: Number of Afternoons in the Desginated Season with an Impact Greater than the Indicated Value .............................. 135 31 Examples of Calculated Plume Visibility Impairment Dependent on Wind Direction, Azimuth of Line of Sight, andViewing Background ........................................ 136 32 Example of Black and White Plume -Terrain Perspective.......... 142 A-1 Two Types of Spatial Distributions of Extra Extinction........ 151 A-2 Change in Sky/Terrain Contrast as a Function of Fractional Increase in Extinction Coefficient for Various Observer -Terrain Distances ............... :............. 157 A-3 Change in Sky/Terrain Contrast as a Function of Fractional Decrease in Visual Range for Various Observer -Terrain Distances .................................... 158 A-4 Change in Sky/Terrain Contrast as a Function of Plume Optical Thickness for Various Observer -Terrain Distances...... 159 E-1 Relative Location of the Proposed Power Plant and Class I Areafor Example 1............................................ 324 E-2 Significant Terrain Features and Possible Plume Trajectories............,,,,.,.,.,, ......... **eeseft000ees 329 E-3 Terrain Elevation Plots ....................................... 330 E-4 Class I Areas within 48-Hour Transport Range at Wind Speedsup to 8 m/s............................................ 333 E-5 Worksheet for the Calculation of Wind Speed and Mixing Depth Joint Frequency Distribution ............................ 335 E-6 Observer -Plume Orientations ................................... 337 E-7 Plan View of Assumed Geometries for Views 1 and 2............. 338 E-8 Plan View of Assumed Geometry for View 3...................... 339 x TABLES 1 Example Table Showing Worst -Case Meteorological Conditions for Plume Discoloration Calculations ............... 78 2 Example Table Showing Worst -Case Limited Mixing Conditions for Haze Calculations .............................. 84 3 Example Tables Showing Computations of Days in a Five - Year Period with the Given Limited Mixing Condition........... 88 4 Wavelength Dependence of Scattering Coefficient as a Function of Particle Size Distribution ...................... 104 5 Example Table Showing Background Atmosphere Phase Functions and Scattering Coefficients ......................... 116 6 Example Summary of the Frequency of Occurrence of Power Plant Plume Discoloration Perceptible from a ClassI Area .................................................. 139 7 Example Summary of Frequency of Occurrence of Increased Haze (Visual Range Reduction) in a Class I Area Due to Power Plant Emissions ......................................... 140 A-1 Summary of Relationships among Parameters Used for Quantifying Increased Atmospheric Haze ........................ 160 E-1 Frequency of Occurrence of SW and WSW Winds by Dispersion Condition and Time of Day .......................... 332 E-2 Frequency of Episode Days by Mixing Depth and Wind Speed...... 334 E-3 Values of oij................................................. 343 E-4 Phase Functions and Scattering Coefficients for Backgroundand Plume .......................................... 351 xi E-5 Comparison -of Example Power Plant Emissions and Appendix D Power Plant Emissions .............................. 357 E-6 Comparison of Selected Scenario Descriptors ................... 357 E-7 Example 2--Cement Plant and Related Operations ................ 360 E-8 Background and Plume atmosphere Phase Functions and Scattering Coefficients ....................................... 368 E-9 Projected Plume Contrast and Contrast Reduction forExample 2................................................. 370 xi i NOMENCLATURE A -- Azimuth angle of line of sight, relative to north babs '- Light absorption coefficient of the air parcel, propor- tional to concentrations of nitrogen dioxide (NO2) and aerosol (like soot) that absorb visible radiation (m"1) bext '" Light extinction coefficient of an air parcel, the sum of absorption and scattering coefficients (m"1) bR -- Light scattering coefficient of particle -free air caused by Rayleigh scatter from air molecules (m"1) bscat -- Light scattering coefficient resulting from Rayleigh scatter (air molecules) and Mie scatter (particles), the sum of bR and bsp (m"1) (bscat/V) -- Light scattering efficiency per unit aerosol volume con- centration (m"1) bsp -- Light scattering coefficient caused by particles only (m 1) C -- Contract at a given wavelength of two colored objects, like plume/sky or sky/terrain Chaze "' Contrast of -a haze layer against the sky above it Cmin -- Contrast that is just perceptible, a threshold contrast Cplume '- Contrast of a plume against a viewing background like the sky on a terrain feature Cr -- Contrast of a terrain feature at distance r against the sky Acr -- Change in sky/terrain contrast caused by a plume or extra extinction CO -- Intrinsic contrast of a terrain feature against the sky. The sky/terrain contrast at r = 0. For a black object, CO = -1. D -- Stack diameter (m) eE(L*a*b*) -- Color difference parameter used to characterize the per- ceptibility of the difference between two colors. In the context of this workbook, it is used to characterize the perceptibility of a plume on the basis of the color dif- ference between the plume and a viewing background like the sky, a cloud, or a terrain feature. Color differences are due to differences in three dimensions: brightness (L*) and color hue and saturation (a*b*) F -- Buoyancy flux of flue gas emissions from a stack (m4s-3) Fs -- Solar insolation or flux incident on an air parcel within a given wavelength band (watt m-2 trail) fobj -- Fraction of total plume optical thickness between an observer and a viewed object g -- Gravitational acceleration ( - 9.8 m s-2) H -- Plume altitude above the ground (m) Hm -- Height of a mixed layer above the ground (m) hstack '- Height of a stack (m) Ah -- Plume rise (m) I -- Light intensity or radiance for a given line of sight and wavelength band (watt m-2sr-1 0-1). Subscripts t and h refer to terrain and horizon, respectively. Iobj -- Light intensity reflected from an object like a terrain feature (watt m-2sr-1W 1) kd -- Rate constant for surface deposition (s-1) kf -- Rate constant for S02-to-SO4- conversion (s'1) p -- Atmospheric dispersion parameter used in the level-1 analysis to calculate the horizontal line -of -sight integral of a plume concentration (s m-2) p(a,o) -- Phase function, a parameter that relates the portion of total scattered light of a given wavelength X that is scattered in a given direction specified by the scattering angle 0 xiv Q -- Emission rate of a species, such as S02, or plume flux at a given downwind distance, which may be less than the emission rate because of surface deposition and chemical conversion (g s-1). Subscripts refer to species con- sidered (e.g., S02, SO4% and particulate) Qscat '- Plume flux of the scattering coefficient above background (m2s-1). Subscripts refer to species considered (e.g., SO4-, primary particulate) R -- Blue -red ratio used in visibility impairment calculations to characterize the coloration of a plume relative to the viewing background RH -- Relative background humidity (percent) r -- Distance along the line of sight from the viewed object to the observer (m) ro -- Object -observer distance (m) rp -- Distance from observer to centroid of plume material (m) rq -- Distance from viewed object to centroid of plume material (m) ry -- Visual range, a parameter characteristic of the clarity of the atmosphere, inversely proportional to the extinction coefficient. H is farthest distance at which a black object is perceptible against the horizon sky (m) rv0 -- Background visual range without plume (m) T -- Temperature in degrees absolute t -- Time (s) u -- Wind speed (m s-1) -- Flue gas volumetric flow rate (m3s'1) v -- Wind velocity vector (m s-1) AV-- Percentage visual range reduction vd -- Deposition velocity (m s-1) WD -- Wind direction x -- Downwind distance from emissions source (m) y -- Cross -wind direction from plume centerline (m) Zsite '- Elevation of a site above mean sea level (m) xv Zblock '- Elevation of the terrain above mean sea level that can be assumed to block the flow of emissions (m) Zs -- Solar zenith angle, the angle between the sun and the normal to the earth's surface z -- Distance above ground (m) a -- Wavelength of light (m) p -- Density of a particle (g m 3) a -- Horizontal angle between a line of sight and the plume centerline B -- Vertical angle between a line of sight and the horizontal X -- Concentration of a given species in an air parcel (g m-3) T -- Optical thickness of a plume, the line -of -sight integral. of the extinction coefficient. Subscripts refer to the component of the total or plume optical thickness (e.g., particulate, SOq-, NO2) Denotes the concentration of the species within brackets w -- Albedo of the plume or background atmosphere, the ratio of the scattering coefficient to the extinction coefficient e -- Scattering angle, the angle between direct solar radiation and the line of sight. If the observer were looking directly at the sun, a would equal 0 % If the observer looked away from the sun, a would equal 180 % xvi Q -- Emission rate of a species, such as S02, or plume flux at a given downwind distance, which may be less than the emission rate because of surface deposition and chemical conversion (g s-1). Subscripts refer to species con- sidered (e.g., S02, SO4-, and particulate) Qscat '" Plume flux of the scattering coefficient above background (m2s"1). Subscripts refer to species considered (e.g., SO4-, primary particulate) R -- Blue -red ratio used in visibility impairment calculations to characterize the coloration of a plume relative to the viewing background RH -- Relative background humidity (percent) r -- Distance along the line of sight from the viewed object to the observer (m) ro -- Object -observer distance (m) rp -- Distance from observer to centroid of plume material (m) rq -- Distance from viewed object to centroid of plume material (m) ry -- Visual range, a parameter characteristic of the clarity of the atmosphere, inversely proportional to the extinction coefficient. H is farthest distance at which a black object is perceptible against the horizon sky (m) rv0 -- Background visual range without plume (m) T -- Temperature in degrees absolute t -- Time (s) u -- Wind speed (m s-1) V -- Flue gas volumetric flow rate (m3s"1) v -- Wind velocity vector (m s-1) AV— Percentage visual range reduction vd -- Deposition velocity (m s"1) WD -- Wind direction x -- Downwind distance from emissions source (m) y -- Cross -wind direction from plume centerline (m) Zsite -- Elevation of a site above mean sea level (m) a xv Zblock -- Elevation of the terrain above mean sea level that can be assumed to block the flow of emissions (m) Zs -- Solar zenith angle, the angle between the sun and the normal to the earth's surface z -- Distance above ground (m) a -- Wavelength of light (m) p -- Density of a particle (g m-3) a -- Horizontal angle between a line of sight and the plume centerline B -- Vertical angle between a line of sight and the horizontal X -- Concentration of a given species in an air parcel (g m-3) T -- Optical thickness of a plume, the line -of -sight integral of the extinction coefficient. Subscripts refer to the component of the total or plume optical thickness (e.g., particulate, SO4-, NO2) Denotes the concentration of the species within brackets w -- Albedo of the plume or background atmosphere, the ratio of the scattering coefficient to the extinction coefficient e -- Scattering angle, the angle between direct solar radiation and the line of sight. If the observer were looking directly at the sun, a would equal 0°. If the observer looked away from the sun, a would equal 180 % xvi Q -- Emission rate of a species, such as S02, or plume flux at a given downwind distance, which may be less than the emission rate because of surface deposition and chemical conversion (g s-1). Subscripts refer to species con- sidered (e.g., S02, SO4% and particulate) Qscat '" Plume flux of the scattering coefficient above background (m2s-1). Subscripts refer to species considered (e.g., SO4-, primary particulate) R -- Blue -red ratio used in visibility impairment calculations to characterize the coloration of a plume relative to the viewing background RH -- Relative background humidity (percent) r -- Distance along the line of sight from the viewed object to the observer (m) ro -- Object -observer distance (m) rp -- Distance from observer to centroid of plume material (m) rg -- Distance from viewed object to centroid of plume material (m) ry -- Visual range, a parameter characteristic of the clarity of the atmosphere, inversely proportional to the extinction coefficient. H is farthest distance at which a black object is perceptible against the horizon sky (m) rv0 -- Background visual range without plume (m) T -- Temperature in degrees absolute t -- Time (s) u -- Wind speed (m s-1) li -- Flue gas volumetric flow rate (m3s-1) v -- Wind velocity vector (m s-1) AV-- Percentage visual range reduction vd -- Deposition velocity (m s-1) WD -- Wind direction x -- Downwind distance from emissions source (m) y -- Cross -wind direction from plume centerline (m) Zsite -- Elevation of a site above mean sea level (m) xv Zblock -- Elevation of the terrain above mean sea level that can be assumed to block the flow of emissions (m) Zs -- Solar zenith angle, the angle between the sun and the normal to the earth's surface z -- Distance above ground (m) a -- Wavelength of light (m) p -- Density of a particle (g m-3) a -- Horizontal angle between a line of sight and the plume centerline B -- Vertical angle between a line of sight and the horizontal X -- Concentration of a given species in an air parcel (g m-3) z -- Optical thickness of a plume, the line -of -sight integral. of the extinction coefficient. Subscripts refer to the component of the total or plume optical thickness (e.g., particulate, SO4-, NOz) Denotes the concentration of the species within brackets w -- Albedo of the plume or background atmosphere, the ratio of the scattering coefficient to the extinction coefficient e -- Scattering angle, the angle between direct solar radiation and the line of sight. If the observer were looking directly at the sun, a would equal 0% If the observer looked away from the sun, a would equal 1800. xvi Q -- Emission rate of a species, such as S02, or plume flux at a given downwind distance, which may be less than the emission rate because of surface deposition and chemical conversion (g s-1). Subscripts refer to species con- sidered (e.g., S02, SO4% and particulate) Qscat '" Plume flux of the scattering coefficient above background (m2s-1). Subscripts refer to species considered (e.g., SO4-, primary particulate) R -- Blue -red ratio used in visibility impairment calculations to characterize the coloration of a plume relative to the viewing background RH -- Relative background humidity (percent) r -- Distance along the line of sight from the viewed object to the observer (m) ro -- Object -observer distance (m) rp -- Distance from observer to centroid of plume material (m) rq -- Distance from viewed object to centroid of plume material (m) ry -- Visual range, a parameter characteristic of the clarity of the atmosphere, inversely proportional to the extinction coefficient. H is farthest distance at which a black object is perceptible against the horizon sky (m) rv0 -- Background visual range without plume (m) T -- Temperature in degrees absolute t -- Time (s) u -- Wind speed (m s-1) -- Flue gas volumetric flow rate (m3s"1) v -- Wind velocity vector (m s-1) AV-- Percentage visual range reduction vd -- Deposition velocity (m s-1) WD -- Wind direction x -- Downwind distance from emissions source (m) y -- Cross -wind direction from plume centerline (m) Zsite '- Elevation of a site above mean sea level (m) xv Zblock --"Elevation of the terrain above mean sea level that can be assumed to block the flow of emissions (m) Zs -- Solar zenith angle, the angle between the sun and the normal to the earth's surface z -- Distance above ground (m) a -- Wavelength of light (m) p -- Density of a particle (g m-3) a -- Horizontal angle between a line of sight and the plume centerline B -- Vertical angle between a line of sight and the horizontal X -- Concentration of a given species in an air parcel (g m-3) z -- Optical thickness of a plume, the line -of -sight integral. of the extinction coefficient. Subscripts refer to the component of the total or plume optical thickness (e.g., particulate, SO4-, NO2) Denotes the concentration of the species within brackets -- Albedo of the plume or background atmosphere, the ratio of the scattering coefficient to the extinction coefficient e -- Scattering angle, the angle between direct solar radiation and the line of sight. If the observer were looking directly at the sun, 8 would equal 0° . If the observer looked away from the sun, 9 would equal 180 % xvi Q -- Emission rate of a species, such as S02, or plume flux at a given downwind distance, which may be less than the emission rate because of surface deposition and chemical conversion (g s-1). Subscripts refer to species con- sidered (e.g., S02, 504% and particulate) Ascat '- Plume flux of the scattering coefficient above background (m2s-1). Subscripts refer to species considered (e.g., SO4-, primary particulate) R -- Blue -red ratio used in visibility impairment calculations to characterize the coloration of a plume relative to the viewing background RH -- Relative background humidity (percent) r -- Distance along the line of sight from the viewed object to the observer (m) ro -- Object -observer distance (m) rp -- Distance from observer to centroid of plume material (m) rq -- Distance from viewed object to centroid of plume material (m) ry -- Visual range, a parameter characteristic of the clarity of the atmosphere, inversely proportional to the extinction coefficient. H is farthest distance at which a black object is perceptible against the horizon sky (m) rv0 -- Background visual range without plume (m) T -- Temperature in degrees absplute t -- Time (s) u -- Wind speed (m s-1) V -- Flue gas volumetric flow rate (m3s-1) v -- Wind velocity vector (m s-1) AV-- Percentage visual range reduction vd -- Deposition velocity (m s-1) WD -- Wind direction x -- Downwind distance from emissions source (m) y -- Cross -wind direction from plume centerline (m) Zsite -- Elevation of a site above mean sea level (m) xv Zblock '- Elevation of the terrain above mean sea level that can be assumed to block the flow of emissions (m) Zs -- Solar zenith angle, the angle between the sun and the normal to the earth's surface z -- Distance above ground (m) a -- Wavelength of light (m) p -- Density of a particle (g m-3) a -- Horizontal angle between a line of sight and the plume centerline B -- Vertical angle between a line of sight and the horizontal X -- Concentration of a given species in an air parcel (g m-3) -- Optical thickness of a plume, the line -of -sight integral. of the extinction coefficient. Subscripts refer to the component of the total or plume optical thickness (e.g., particulate, SOq-, NO2) Denotes the concentration of the species within brackets w -- Albedo of the plume or background atmosphere, the ratio of the scattering coefficient to the extinction coefficient 8 -- Scattering angle, the angle between direct solar radiation and the line of sight. If the observer were looking directly at the sun, a would equal 0% If the observer looked away from the sun, 8 would equal 1800. xvi Q -- Emission rate of a species, such as S02, or plume flux at a given downwind distance, which may be less than the emission rate because of surface deposition and chemical conversion (g s-1). Subscripts refer to species con- sidered (e.g., S02, SO4 % _and particulate) Qscat '" Plume flux of the scattering coefficient above background (m2s-1). Subscripts refer to species considered (e.g., SO4-, primary particulate) R -- Blue -red ratio used in visibility impairment calculations to characterize the coloration of a plume relative to the viewing background RH -- Relative background humidity (percent) r -- Distance along the line of sight from the viewed object to the observer (m) ro -- Object -observer distance (m) rp -- Distance from observer to centroid of plume material (m) rq -- Distance from viewed object to centroid of plume material (m) ry -- Visual range, a parameter characteristic of the clarity of the atmosphere, inversely proportional to the extinction coefficient. H is farthest distance at which a black object is perceptible against the horizon sky (m) rv0 -- Background visual range without plume (m) T -- Temperature in degrees absolute t -- Time (s) u -- Wind speed (m s-1) V -- Flue gas volumetric flow rate (m3s-1) v -- Wind velocity vector (m s"1) AV-- Percentage visual range reduction vd -- Deposition velocity (m s-1) WD -- Wind direction x -- Downwind distance from emissions source (m) y -- Cross -wind direction from plume centerline (m) Zsite -- Elevation of a site above mean sea level (m) xv Zblock '- Elevation of the terrain above mean sea level that can be assumed to block the flow of emissions (m) Zs -- Solar zenith angle, the angle between the sun and the normal to the earth's surface z -- Distance above ground (m) a -- Wavelength of light (m) a -- Density of a particle (g m-3) a -- Horizontal angle between a line of sight and the plume centerline B -- Vertical angle between a line of sight and the horizontal X -- Concentration of a given species in an air parcel (g m-3) z -- Optical thickness of a plume, the line -of -sight integral of the extinction coefficient. Subscripts refer to the component of the total or plume optical thickness (e.g., particulate, SO4% NO2) Denotes the concentration of the species within brackets w -- Albedo of the plume or background atmosphere, the ratio of the scattering coefficient to the extinction coefficient e -- Scattering angle, the angle between direct solar radiation and the line of sight. If the observer were looking directly at the sun, a would equal 00. If the observer looked away from the sun, a would equal 180 % xvi Q -- Emission rate of a species, such as S02, or plume flux at a given downwind distance, which may be less than the emission rate because of surface deposition and chemical conversion (g s-1). Subscripts refer to species con- sidered (e.g., 502, SO4% and particulate) ' Qscat -- Plume flux of the scattering coefficient above background (m2s-1). Subscripts refer to species considered (e.g.,. SO4-, primary particulate) R -- Blue -red ratio used in visibility impairment calculations to characterize the coloration of a plume relative to the viewing background RH -- Relative background humidity (percent) r -- Distance along the line of sight from the viewed object to the observer (m) ro -- Object -observer distance (m) rp -- Distance from observer to centroid of plume material (m) rq -- Distance from viewed object to centroid of plume material (m) ry -- Visual range, a parameter characteristic of the clarity of the atmosphere, inversely proportional to the extinction coefficient. H is farthest distance at which a black object is perceptible against the horizon sky (m) rv0 -- Background visual range without plume (m) T -- Temperature in degrees absolute t -- Time (s) u -- Wind speed (m s-1) V -- Flue gas volumetric flow rate (m3s-1) v -- Wind velocity vector (m s-1) AV-- Percentage visual range reduction vd -- Deposition velocity (m s-1) WD -- Wind direction x -- Downwind distance from emissions source (m) y -- Cross -wind direction from plume centerline (m) Zsite -- Elevation of a site above mean sea level (m) xv Zblock '- Elevation of the terrain above mean sea level that can be assumed to block the flow of emissions (m) Zs -- Solar zenith angle, the angle between the sun and the normal to the earth's surface z -- Distance above ground (m) a -- Wavelength of light (m) p -- Density of a particle (g m-3) a -- Horizontal angle between a line of sight and the plume centerline 6 -- Vertical angle between a line of sight and the horizontal X -- Concentration of a given species in an air parcel (g m-3) T --'Optical thickness of a plume, the line -of -sight integral. of the extinction coefficient. Subscripts refer to the component of the total or plume optical thickness (e.g., particulate, SOq-, NO2) Denotes the concentration of the species within brackets w -- Albedo of the plume or background atmosphere, the ratio of the scattering coefficient to the extinction coefficient e -- Scattering angle, the angle between direct solar radiation and the line of sight. If the observer were looking directly at the sun, a would equal 00. If the observer looked away from the sun, a would equal 180 % xvi Q -- Emission rate of a species, such as S02, or plume flux at a given downwind distance, which may be less than the emission rate because of surface deposition and chemical conversion (g s-1). Subscripts refer to species con- sidered (e.g., S02, SO4% and particulate) Qscat "' Plume flux of the scattering coefficient above background (m2s-1). Subscripts refer to species considered (e.g., SO4-, primary particulate) R -- Blue -red ratio used in visibility impairment calculations to characterize the coloration of a plume relative to the viewing background RH -- Relative background humidity (percent) r -- Distance along the line of sight from the viewed object to the observer (m) ro -- Object -observer distance (m) rp -- Distance from observer to centroid of plume material (m) rq -- Distance from viewed object to centroid of plume material (M) ry -- Visual range, a parameter characteristic of the clarity of the atmosphere, inversely proportional to the extinction coefficient. H is farthest distance at which a black object is perceptible against the horizon sky (m) rv0 -- Background visual range without plume (m) T -- Temperature in degrees absolute t -- Time (s) u -- Wind speed (m s-1) -- Flue gas volumetric flow rate (m3s-1) v -- Wind velocity vector (m s-1) AV-- Percentage visual range reduction vd -- Deposition velocity (m s-1) WD -- Wind direction x -- Downwind distance from emissions source (m) y -- Cross -wind direction from plume centerline (m) Zsite -- Elevation of a site above mean sea level (m) xv Zblock '- Elevation of the terrain above mean sea level that can be assumed to block the flow of emissions (m) Zs -- Solar zenith angle, the angle between the sun and the normal to the earth's surface z -- Distance above ground (m) a -- Wavelength of light (m) p -- Density of a particle (g m 3) a -- Horizontal angle between a line of sight and the plume centerline B -- Vertical angle between a line of sight and the horizontal X -- Concentration of a given species in an air parcel (g m-3) T -- Optical thickness of a plume, the line -of -sight integral. of the extinction coefficient. Subscripts refer to the component of the total or plume optical thickness (e.g., particulate, SO4% NO2) Denotes the concentration of the species within brackets w -- Albedo of the plume or background atmosphere, the ratio of the scattering coefficient to the extinction coefficient e -- Scattering angle, the angle between direct solar radiation and the line of sight. If the observer were looking directly at the sun, a would equal 0% If the observer looked away from the sun, a would equal 180 % xvi Q -- Emission rate of a species, such as S02, or plume flux at a given downwind distance, which may be less than the emission rate because of surface deposition and chemical conversion (g s-1). Subscripts refer to species con- sidered (e.g., S02, SO4% and particulate) Qscat '- Plume flux of the scattering coefficient above background (m2s-1). Subscripts refer to species considered (e.g., SO4-, primary particulate) R -- Blue -red ratio used in -visibility impairment calculations to characterize the coloration of a plume relative to the viewing background RH -- Relative background humidity (percent) r -- Distance along the line of sight from the viewed object to the observer (m) ro -- Object -observer distance (m) rp -- Distance from observer to centroid of plume material (m) rq -- Distance from viewed object to centroid of plume material (m) ry -- Visual range, a parameter characteristic of the clarity of the atmosphere, inversely proportional to the extinction coefficient. H is farthest distance at which a black object is perceptible against the horizon sky (m) rv0 -- Background visual range without plume (m) T -- Temperature in degrees absolute t -- Time (s) u -- Wind speed (m s-1) 11 -- Flue gas volumetric flow rate (m3s-1) v -- Wind velocity vector (m s-1) AV-- Percentage visual range reduction vd -- Deposition velocity (m s-1) WD -- Wind direction x -- Downwind distance from emissions source (m) y -- Cross -wind direction from plume centerline (m) Zsite -- Elevation of a site above mean sea level (m) xv Zblock "" Elevation of the terrain above mean sea level that can be assumed to block the flow of emissions (m) Zs -- Solar zenith angle, the angle between the sun and the normal to the earth's surface z -- Distance above ground (m) a -- Wavelength of light (m) p -- Density of a particle (g m-3) a -- Horizontal angle between a line of sight and the plume centerline B -- Vertical angle between a line of sight and the horizontal X -- Concentration of a given species in an air parcel (g m-3) T -- Optical thickness of a plume, the line -of -sight integral of the extinction coefficient. Subscripts refer to the component of the total or plume optical thickness (e.g., particulate, SO4-, NO2) Denotes the concentration of the species within brackets w -- Albedo of the plume or background atmosphere, the ratio of the scattering coefficient to the extinction coefficient e -- Scattering angle, the angle between direct solar radiation and the line of sight. If the observer were looking directly at the sun, a would equal 0 % If the observer looked away from the sun, a would equal 180 % xvi Q -- Emission rate of a species, such as S02, or plume flux at a given downwind distance, which may be less than the emission rate because of surface deposition and chemical conversion (g s-1). Subscripts refer to species con- sidered (e.g., S02, SO4% and particulate) ' Qscat -- Plume flux of the scattering coefficient above background (m2s-1). Subscripts refer to species considered (e.g., SO4-, primary particulate) R -- Blue -red ratio used in visibility impairment calculations to characterize the coloration of a plume relative to the viewing background RH -- Relative background humidity (percent) r -- Distance along the line of sight from the viewed object to the observer (m) ro -- Object -observer distance (m) rp -- Distance from observer to centroid of plume material (m) rq -- Distance from viewed object to centroid of plume material (m) ry -- Visual range, a parameter characteristic of the clarity of the atmosphere, inversely proportional to the extinction coefficient. H is -farthest distance at which a black object is perceptible against the horizon sky (m) rv0 -- Background visual range without plume (m) T -- Temperature in degrees absolute t -- Time (s) u -- Wind speed (m s-1) 11 -- Flue gas volumetric flow rate (m3s-1) v -- Wind velocity vector (m s-1) eV-- Percentage visual range reduction vd -- Deposition velocity (m s-1) WD -- Wind direction x -- Downwind distance from emissions source (m) y -- Cross -wind direction from plume centerline (m) Zsite -- Elevation of a site above mean sea level (m) xv Zblock Elevation of the terrain above mean sea level that can be assumed to block the flow of emissions (m) Zs -- Solar zenith angle, the angle between the sun and the normal to the earth's surface z -- Distance above ground (m) X -- Wavelength of light (m) p -- Density of a particle (g m 3) a -- Horizontal angle between a line of sight and the plume centerline -- Vertical angle between a line of sight and the horizontal X -- Concentration of a given species in an air parcel (g m-3) T -- Optical thickness of a plume, the line -of -sight integral. of the extinction coefficient. Subscripts refer to the component of the total or plume optical thickness (e.g., particulate, SO4-, NO2) Denotes the concentration of the species within brackets w -- Albedo of the plume or background atmosphere, the ratio of the scattering coefficient to the extinction coefficient e -- Scattering angle, the angle between direct solar radiation and the line of sight. If the observer were looking directly at the sun, a would equal 0% If the observer looked away from the sun, a would equal 180 % xvi 1 INTRODUCTION The Clean Air Act Amendments of 1977 require evaluation of new and existing emissions sources to determine potential impacts on visibility in class I areas.* These source evaluations are to be used as part of a regulatory program to prevent future and remedy existing impairment of visibility in mandatory class I federal areas that results from man-made air pollution. This workbook is designed to provide the air pollution analyst with technical guidance in determining the potential impacts of an emissions source on class I area visibility. It should be useful in siting studies, emissions control specification, environmental impact statements, and new source reviews, and it may also be used in conjunction with measurements of existing emissions sources to assess the potential requirements for emissions control retrofit technology. It is beyond the scope of this document to address the cumulative impacts of multiple sources on regional haze. Rather, the emphasis is on the incremental visual impact of a single emissions source. Although this workbook can be used independently, we highly recommend that the analyst read the following documents: > U.S. Environmental Protection Agency (October 1979), "Protecting Visibility: An EPA Report to Congress," EPA- 450/5-79-008, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina. > Latimer, D. A., et al. (September 1978), "The Development of Mathematical Models for the Prediction of Anthropogenic Visibility Impairment," EPA-450/3-78-110a,b,c, U.S. * Class T area as used to this document means Federal Class I area. 1 Environmental Protection Agency, Research Triangle Park, North Carolina. > Turner, D. B. (1969), "Workbook of Atmospheric Dispersion Other guidance documents on visibility, including those below, should also be consulted: > User's Manual for the Plume Visibility Model (PLUVUE), EPA-450/4-30-032. > Interim Guidance for Visibility Monitoring, EPA-450/2-80-082 > Guidelines for Determining Best Available Retrofit Technology for Coal -Fired Power Plants and Other Major Stationary Sources, EPA-450/3-80-0096. 1.1 CLASSES OF VISIBILITY IMPAIRMENT Two separate classes of visibility impairment are of concern in this workbook: > Atmospheric discoloration. > Visual range reduction (increased haze). Plumes from power plants or other combustion sources may be discol- ored because of NOx emissions that are converted in the atmosphere to the reddish -brown gas, nitrogen dioxide. However, particle emissions and sec- ondary aerosols formed from gaseous precursor emissions may also discolor the atmosphere. Increased haze is caused principally by primary particu- late emissions and secondary aerosols, such as sulfate. Worst -case impacts associated with these two classes of visibility impairment occur during two distinctly different kinds of atmospheric con- ditions. On one hand, atmospheric discoloration is greatest during periods of stable, light winds that occur after periods of nighttime transport. These conditions result in maximum particle and NO2 line-of- 2 sight integrals that could cause maximum plume coloration. However, because a plume remains intact during such conditions, discoloration would be limited to a shallow vertical layer in the atmosphere. General atmos- pheric clarity would not be impaired, but the plume or layer could have an adverse visual impact, degrading the scenic beauty of a vilta. The plume might be perceptible and discolored enough to interfere with a visitor's enjoyment of a class I area. on the other other hand, increased general haze (decreased visual range) is greatest during light wind, limited mixing, or stagnation condi- tions after daytime transport, because conversion of gaseous precursor emissions to secondary aerosol is more rapid during these conditions, when an individual plume or discolored layer may not be perceptible at all. Rather, the impact would be manifested by an increased haze and loss of clarity in landscape features. Also, since the impact of any one emis- sions source may be small when compared to regional emissions, incremental impacts must be considered in light of the magnitude and frequency of increased haze caused by other natural and man-made emissions sources in the region. Increased haze may be a particularly severe problem in areas where ventilation is limited by terrain obstacles such as canyon walls, mountain ranges, plateaus, and river valleys. In such areas, emissions could accumulate over a period of a few days. Diurnal upslope and down - slope (drainage) winds can cause a "sloshing" air motion that could trap emissions in a valley. Although ground -level contaminant concentrations might be very low in such a situation, increased haze could be a problem. EPA has published regulations concerning the protection of visibility as Subpart P of Part 51 Title 40 of the Code of Federal Regulations. Tie regulations define "visibility impairment" to mean any humanly perceptible change in visibility Cvisual range, contrast, coloration) f•om that which would have existed under natural conditions. Definitions for "adverse impact on visibility" and "significant impairment" are also provided t'n the regulations. States are required to establish pro- cedures for use in conducting visibility impact analyses. An important part of a visibility impact analysis is to determine the K frequency of occurrence and magnitude of visual impact in or within view of a class ,I area. 1.2 APPROACH USED IN THIS WORKBOOK This workbook outlines a screening procedure that will expedite the analysis of an emissions source. Figure 1 shows a schematic diagram of this screening procedure. Potentially, one could analyze a given source at any one of three basic levels of detail. A level-1 analysis involves a series of conservative screening tests that permit the analyst to elimi- nate -sources with little potential for adverse or significant visibility impairment. A simple screening calculation, requiring only a few minutes of an analyst's time, indicates whether a source could cause significant impairment during hypothetical, worst -case meteorological conditions. If not, further analysis is unnecessary. If impairment is indicated, a level-2 analysis would be performed. The level-2 screening procedure is similar to the level-1 analysis in that its purpose is to estimate impacts during worst -case meteorological conditions; however, more specific infor- mation regarding the source, topography, regional visual range, and mete- orological conditions is assumed to be available. A frequbncy-of-occur- rence analysis is performed to determine conditions representative of the worst day in a year. Whereas the level-1 analysis requires only a few minutes, the level-2 analysis may require several days. In this workbook several options are recommended for performing a level-2 analysis: (1) use of hand calculations based on the formulas, tables, and graphs pre- sented here, (2) use of reference tables and figures presented in the appendixes, and (3) use of the computer -based plume visibility model. Finally, if both the level-1 and level-2 analyses indicate the possi- bility of significant or adverse visibility impairment, a more detailed * It is important to note that emissions may not have to be transported into a class I area to cause visual impact in a class 1 area. If a vista within a class I area has views of landscape features outside that area that are considered by the federal land manager to be an integral part of the class I area experience, that vista may be protected. 4 LEVEL-1 ANALYSIS AND TESTS LEVEL-2 ANALYSIS AND TESTS LEVEL-3 ANALYSIS AND TESTS INPUT: • NOx, S02, PARTICULATE EMISSIONS • REGIONAL VISUAL RANGE • DISTANCE TO CLASS I AREA INPUT: • SIZE DISTRIBUTION • METEOROLOGICAL DATA • TOPOGRAPHY • AMBIENT DATA INPUT: • JOINT FREQUENCIES OF WIND SPEED. WIND DIR- ECTION, STABILITY. MIXING DEPTH, AND BACKGROUND OZONE CON- CENTRATION AND VISUAL RANGE CALCULATE CONTRAST VALUE Ci, C2, AND C3 BASED ON iIORST-CASE ASSUMPTIONS / IS C11 iC21 NO C31 > 0.1 Yes CALCULATE WORST -DAY VISUAL IMPACTS BASED ON ACTUAL AREA CONDITIONS USING ONE OF THE FOLLOWING: 1 HAND CALCULATIONS 2 REFERENCE TABLES 3 REFERENCE FIGURES 4 COMPUTER MODEL VISUAL IMPACT PARAM- ETERS GREATER THAN CRITERIA VALUES? / YES CALCULATE MAGNITUDE.AND FREQUENCY OF OCCURRENCE OF VISUAL IMPACT USING MODELS. DATA, AND OTHER TECHNIQUES 01, IS ` IMPACT OR SIGNIFICANT -.,BY GOVERN- i Yes VISUAL IMPACT IS JUDGED TO BE ADVERSE OR SIGNIFICANT, No ANALYZE ALYERNATIVES: • BETTER EMISSIONS CONTROLS • ALTERNATIVE SITES • SCALED -DOWN SOURCE SIZE • CANCEL PLANS FOR SOURCE ADVERSE OR SIGNIFICANT ISIBILITY IM- PAIRMENT / LIKELY 01 NO ADVERSE OR SIGNIFICANT ISIBILITY II PAIRMENT LIKELY / VISUAL IMPACT IS NOT JUDGED TO BE ADVERSE OR LSIGNIFICANT/ Figure 1. Schematic of visibility screening analysis procedure. The numerical meaning of the terms "significant" and "adverse" differ on a case -by -case basis and will be defined after an in-depth policy analysis of each case. level-3 analysis is recommended. The purpose of a level-3 analysis is to provide an accurate description of the magnitude and frequency of occur- rence of impact. For this level of analysis, a visibility model is used. The number of days per year and season in which a given magnitude of impact occurs are calculated from joint frequency tables of wind speed, wind direction, stability, mixing depth, ozone concentration, and visual range in the area. Computer graphics can be used to display the appearance of plumes or haze layers in black and white or in color. Detailed analyses of the spatial and temporal distribution of windfields and the effect on visual impacts may be made. For existing sources, measurements of visual impacts can be used in place of, or in combination with, the model calculations. As shown in figure 1, there are tests that the analyst can apply after the level-1 and level-2 analyses to determine if there is a potential for adverse or significant impairment. If these tests show little potential for adverse or significant impacts, the analyst may choose to make a recommendation on the basis of these less detailed analyses. In some situations, however, even though the level-1 or level-2 test shows that impacts are not likely to be adverse or significant, the analyst may choose to use more detailed analytic procedures such as those suggested for the level-3 analysis. This might be the case if the emis- sions source barely passes the level-1 or level-2 test. Also, special meteorological conditions such as stagnation, terrain -influenced disper- sion, and complex photochemistry (if the source emits reactive hydro- carbons, is located in an urban area, or is affected by an urban plume) may require further detailed analysis. We have attempted to make this workbook a straightforward, easy -to - use reference manual; however, before we present the details of the visi- bility screening analysis procedures, we feel it is necessary to describe some of the concepts and theories upon which they are based. These are presented in chapter 2. The level-1 and level-2 analyses and tests are presented in chapters 3 and 4. Suggestions for more detailed analyses (level-3) are presented in chapter 5. 2 GENERAL CONCEPTS In this chapter we present the general conceptual approach used throughout this workbook. We recommend that the user of this document read this chapter and the reference material cited in chapter 1 before using the procedures presented in the following three chapters for the level-1, -2, and -3 visibility screening analyses. Here we discuss the following subjects: > Atmospheric optics and visibility impairment. > Plume -observer geometry. > Characterization of the frequency of occurrence of visual impacts. 2.1 PHYSICAL CONCEPTS RELATED TO VISIBILITY IMPAIRMENT 2.1.1 Visual Perception Human visual perception occurs when the eye is exposed to light (i.e., electromagnetic radiation within the visible spectrum, 0.4 to 0.7 tiara). Furthermore, the eye must be exposed to light of different intensities or wavelength mixtures before one perceives objects in the outside world. Since objects are usually viewed through the atmosphere (unless the observer is under water or in outer space), atmospheric con- taminants can affect what one perceives visually. This is the crux of the visibility impairment issue: what impact does air pollution have on our visual perception, particularly of scenic areas? Through recent perceptual research, Land (1977) has found that the eye -brain mechanism responds to objects within the field of view using a VA comparison procedure. We compare light intensities of different objects at different wavelengths in the visual field. Through this comparison we perceive whether an object is visible, whether it is lighter or darker than neighboring objects, and whether it is more or less blue, green, or red than neighboring objects. A convenient way to describe this light intensity comparison is by a ratio such as where I1 and I2 are the spectral radiances (light intensities) of two objects, 1 and 2, at wavelength a in the visible spectrum (0.4 < a < 0.7 on) . Another way to describe this comparison of light intensities is to use contrast: C(a)-I1(�)_ 12(a)� I1(x)-1 2 X Tr. Note that if C(X) = 0 for all wavelengths a, then I1 = I2 and there would be no perceptible difference in the two objects defined by I1 and 12. When we say there is much contrast in a given scene, then at least for some wavelengths, C(a) * 0. Air pollution is visually perceptible only if it changes the contrast of objects at different wavelengths in the visible spectrum. 2.1.2 Fundamental Causes of Risibility Impairment The -effects of air pollution are visually perceptible as a result of the following interactions in the atmosphere: 0 > Light scattering - By molecules of air - By particles > Light absorption - By gases - By particles. Light scattering by gaseous molecules of air (Rayleigh scattering), which causes the blue color of the atmosphere, is dominant when the air is relatively free of aerosols and light -absorbing gases. Light scattering by particles is the most important cause of visual range reduction. Fine solid or liquid particulates, whose diameters range from 0.1 to 1.0 pan, are most effective per unit mass in scattering light. Light absorption by gases is particularly important in the discussion of anthropogenic visibility impairment since nitrogen dioxide, a major constituent of power plant plumes, absorbs light. Nitrogen dioxide is reddish -brown because it absorbs strongly at the blue end of the visible spectrum while allowing light at the red end to pass through. Light absorption by particles is important when black soot (finely divided carbon) is present. Anthropogenic contributions to visibility impairment result from the emission of primary particulate matter (such as fly ash, acid and water droplets, soot, and fugitive dust) and of pollutant precursors that are converted in the atmosphere into the following secondary species: > Nitrogen dioxide (NO2) gas from emissions of nitric oxide (NO). > Sulfate (SO4-) particles from SOx emissions. > Nitrate (NO3-) particles from NOx emissions. > Organic particles from hydrocarbon emissions. Before particulate control technology was commonly employed, primary particulate matter, such as smoke, windblown dust, or soot, was a major contributor to visibility impairment, because emissions sources emit pri- mary particles of fly ash and combustion -generated particulates to the atmosphere. If such sources are equipped with efficient abatement equip- ment, the emission rate of primary particles may be small. However, some emissions escape the control equipment and do contribute to the ambient particulate concentration and hence to general visibility impairment. If the emission rate of primary particulates is sufficiently large, the plume itself may be visible. In the past, many older emissions sources generated conspicuous, visible plumes resulting from the large emission rates of primary par- ticulate matter. New plants and old plants still in operation have bene- fited from more efficient particulate abatement equipment and a state of the art in which particulate removal efficiencies in excess of 99.5 percent are commonly specified and achieved. In addition, with the installation of flue gas desulfurization systems (scrubbers), and with combustion modifications, sulfur dioxide and nitrogen oxide emissions have also been reduced. As a result, the visual impact of emissions has been sharply reduced, as evidenced by the nearly invisible plumes under most conditions of modern coal-fired power plants. Unfortunately, however, the contribution to visibility impairment of the secondary pollutants — nitrogen nitrogen dioxide gas and sulfate, nitrate, and organic aerosol --is now becoming increasingly evident and is of growing concern. Since nitrogen dioxide absorbs light selectively, it can discolor the atmosphere, causing a yellow or brown plume when present in sufficient concentrations. Almost all of the nitrogen oxide emitted from emissions sources is nitric oxide, a colorless gas. But chemical reactions in the atmosphere can oxidize a substantial portion of the colorless NO to the reddish -brown NO2. Secondary sulfate, nitrate, and organic particles have a dominating effect on visual range in many situations because these particles range in size from 0.1 to 1.0 um in diameter, which is the most efficient size per unit mass for light scattering. As is discussed later, submicron aerosol 10 (with diameters in the range from 0.1 to 1.0 pm) is 10 times more effec- tive in light scattering than the same mass of coarse (> 1 un) aerosol. Also, because secondary aerosol forms slowly in the atmosphere, maximum aerosol concentrations and associated visibility impairment may occur at large distances from emissions sources. 2.1.3 Atmospheric Optics The effect of the intervening atmosphere on the visibility and coloration of a viewed object (e.g., the horizon sky, a mountain, a cloud) can be calculated by solving the radiation transfer equation along the line of sight. As we noted earlier, the effects of air pollution are visually perceptible because of contrast. Thus, visibility impairment can be quantified by comparing the intensity or the coloration of two objects (e.g., a distant mountain against the horizon sky). The effect of the intervening atmosphere on the light intensity of the viewed object can be determined if the concentration and characteristics of air molecules, aerosol, and nitrogen dioxide are known along the line of sight. The change in spectral light intensity or spectral radiance I(a) as a function of distance along the sight path at any point in the atmosphere can be calculated (neglecting multiple scattering*) as follows: ddr X) = -bext (�) I ( X) + p (4 no) bsc at ( a) Fs ( X) (1) * Multiple scattered radiation is scattered (or reflected) more than once. Although the plume visibility model treats multiple scattering, it is beyond the scope of the hand calculations presented in this workbook to do so. Reasonably accurate solutions are obtained for the contrast parameters used to characterize visibility impairment in this workbook even if multiple scattering is ignored. 11 where r = the distance along the sight path from the object to the observer, p(e) = the scattering distribution or phase function for scattering angle- a [see figure 2(a) for defini- tions], Fs = the solar flux (watt/m2 /un) incident on the atmosphere, bscat = the scattering coefficient, which is the sum of the Rayleigh scattering (due to air molecules), bR, and the scattering due to particles, bsp: bscat( a) = b R ( a) + bsp( a) (2) bext = the sum of the scattering, bsp, and absorption coefficients, babs: bext( a) - bscat( a) + babs( a) (3) On the right-hand side of equation (1), the first term represents light absorbed or scattered out of the line of sight; the second term represents light scattered into the line of sight. The values of bscat and babs can be evaluated if the aerosol and NO2 concentrations and such Characteristics as the refractive index and the size distribution of the aerosol are known. Except in the cleanest atmospheres, bscat is dominated by bsp; also, unless soot is present, babs is dominated by the absorption coefficient due to NO2. Scattering and absorption are wavelength - dependent, and effects are greatest at the blue end ( a = 0.4 un) of the visible spectrum (0.4 < a < 0.7 un). The Rayleigh scattering coefficient bR is proportional to a 4; the scattering coefficient caused by particles is generally proportional to A n, where 0 < n < 2. Also, NO2 absorption is greatest at the blue end. This wavelength dependence causes the dis- coloration of the atmosphere. 12 SUN 70� SCATTERING ANGLE e r OBJECT ENITH ELEMENTAL VOLUME ANGLE (CO' TAINING AIR, ,PARTICLES, AND NO2) LINE OF SIGHT I �dr-4 I { dI OBSERVER (a) Geometry Object -Observer Distance ro ry (b) Visual Range ry (Homogeneous Atmosphere) Figure 2. Effect of an atmosphere on the perceived light • intensity of objects. 13 For a uniform atmosphere, without inhomogeneities caused by plumes (where bscat and bext do not vary with distance r along the line of sight), equation (1) can be solved to find the intensity and coloration of the horizon sky (neglecting multiple scattering): I (X) = p(a,o) bscat(F (4) h 4 n e x��— s The perceived intensity of distant bright and dark objects will approach this intensity as an asymptote, as illustrated by figure 2(b). The visual range ry is the distance at which a black object is barely perceptible against the horizon sky, which occurs when the perceived light intensity of the black object is (1 + Cmin)Ih, where Cmin is the liminal (barely perceptible) contrast, commonly assumed to be -0.02. When equation (1) is solved for rv, for a uniform atmosphere, ry is independent of p(o) and Fs(a) and can be calculated- using Koschmieder's equation: r = - in(Cmin) = 3.912 (5) vb ext e�( X) where bext(a) is evaluated at the middle of the visible spectrum (to which the human eye is most sensitive) and where a = 0.55 vm. The visual range for a nonuniform atmosphere (e.g., a plume case) must be calculated by evaluating equation (1) for the appropriate conditions of the given situa- tion. Atmospheric coloration is determined by the wavelength -dependent scattering and absorption in the atmosphere. The spectral distribution of 1(a) for a over the visible spectrum determines the perceived color and light intensity of the viewed object. The relative contributions of scat- tering (aerosols plus air) and absorption (NO2) to coloration can be illustrated by rearranging equation (1): 14 dI I � dr - bscat(�) nI a s - 1 - babs(�) (6) Note from equation (4) that when light absorption is negligible com- pared with light scattering, the clear horizon intensity is simply (if multiple scattering is ignored): p (a, e) F (a) Ih0( a) = 4n s (7) We now can rewrite equation (6): 1 d_.I,.( = b ( a) I hO b ( a) (8 ) I 7► dr scat I a abs Equation (8) is thus an expression relating the effects of light scattering and light absorption to the change in spectral light intensity with distance along a sight path. On the right-hand side of equation (8), the first term is the.effect o- light scattering, and the second term is the effect of light absorption (NO2). As noted previously, since bscat and babs (due to NO2) are strong functions of wavelength and are greater at the blue end (a = 0.4 um), atmospheric coloration can result. Equation (8) makes clear that NO2 always tends to cause a decrease in light intensity and a yellow -brown coloration by preferentially absorbing blue light, whereas particles may cause a blue -white or a yellow -brown coloration, depending on the value of the quantity in the brackets. If, at a given point along the sight path, I(a) is greater than the clean horizon sky intensity IhO N 9 then the quantity in brackets in the first term on the right-hand side of equation (8) will be negative, which means that the net effect of scattering will be to remove predominantly blue 15 light from the line of sight. This effect would occur if a bright, white cloud or distant snowbank were observed through an aerosol that did not contain NO2; scattering would cause a yellow -brown coloration. If, however, IN is less than Ih0(a), then the quantity in brackets in equation (8) will be positive, which means that the net effect of scatter- ing will be to add predominantly blue light into the line of sight. This effect would occur if a distant, dark mountain were observed through an aerosol that did not contain NO2; scattering would cause the mountain to appear lighter and bluish. Only light absorption can cause I(a) to be less than Ih0( a), and whenever I( a) < IhO( a), scattering will add light to the sight path, thereby masking the coloration caused by NO2 light absorp- tion. The mathematical expressions used in this workbook are simply solu- tions to equation (1) for different boundary conditions and for different values of bscat, bext, p(0) and Fs as they are affected by natural and man-made light scatterers and absorbers. The plume visibility model uses similar formulations, but it also accounts for multiple scattering effects. 2.1.4 Plume Visual Impacts Let us consider now the geometry shown in figure 3, namely, the case of a plume embedded in an otherwise uniform, background atmosphere. Equation (1) can be solved for the spectral radiance at the observer location Po as follows: 16 PO OBSERVER BACKGROUND ATMOSPHERE rp Arp ro BACKGROUND ATMOSPHERE is Figure 3. Object -observer geometry with plume. 17 I(a,ro) Ih 1 - exp (-bextrp) + F T P 1 e w l ume 1- exp (-'p l ume ) exp (-bextr ) P um p P p + I 1 - exp(-bextrq) [exp (- plume]'[exp(-b extrp )] + Iobj [exp(-b e Xtr q ) [exP(-Tplume ) [exp(-b ext r P ) (9) where I(x,ro) = spectral radiance at observer point Po, Ih = horizon sky radiance, assuming the atmosphere is uniform and optically thick (i.e., earth curvature can be ignored); see equation (4) and figure 2(b), rp : plume -observer distance; see figure 3, pplume = average plume phase function, corrected for multiple scattering effects albedo, plume - average plume albedo _ J bscatdr J bextdr "Plume = plume optical thickness (increment above background) plume bextdr = f plume (bscat + babs )dr , rq = distance between viewed object and plume; see f i gure 3, ro =- total distance from viewed object and observer; see figure 3. If the plume is treated as a point, then ro = rp + rq . 18 Note that other variables were defined previously and that all the optical variables (Fs, Ih, bscat, bext, pplume' plume and 'plume) are functions of wavelength X. Further, note that Ih and pplume are dependent on the scattering angle 0 (see figure 2(a) for a definition). Each term on the right-hand side of equation (9) has a physical meaning. The first term represents light scattered into the line of sight by the background atmos- phere between points P2 and Po. The second term represents the light scattered into the line of sight by the plume material. The third term represents the light scattered into the line of sight by the background atmosphere between the object and P1. The fourth and last term represents the light reflected from the object and transmitted to the observer. 2.1.5 Characterizing Visibility Impairment Figure 4 illustrates five situations in which air pollution is visually perceptible. There are two basic kinds of visibility impacts. In one case, of which figures 4(b), (c), and (e) are examples, air pollu- tion is perceptible as a result of the comparison of two objects viewed simultaneously by an observer. The haze layer and plume in figures 4(b) and (c), for example, are perceptible because they contrast with the back- ground atmosphere. The plume in figure 4(e) is perceptible because it contrasts with the viewed objects; in other words, it is brighter or darker or colored differently from the viewed object. In the other case, of which figures 4(a) and (d) are examples, perception of pollution results from the difference between the presently observed scene and the scene remembered under clear conditions. For example, the haze in figure 4(c) may be perceptible because it is colored differently from what is considered normal sky color; it appears white, gray, yellow, or brown instead of blue. The situation shown in figure 4(d) is similar. The scene may appear hazy because the contrast of viewed objects is decreased from that observed on a clear day. Each of these situations can be described either by a set of single contrast values for different wavelengths or by a set of contrast differ- ences for different wavelengths; the cases shown in figures 4(a), (b), and 19 (a) General, uniformly discolored haze (b) Surface -based haze layer contrasting with background atmosphere above 1W �� •� j v (c) Elevated plume or haze layer contrasting with background atmosphere above and below Figure 4. Five basic situations in which air pollution is visually perceptible. m (d) General haze reducing contrast of viewed objects (e) Elevated plume or ground -based or elevated haze layer reducing contrast of a portion of a viewed object Figure 4 (Concluded) 21 (:) can be characterized by contrast, whereas those shown in figures 4(d) and (e) can be characterized by contrast differences. We can use equation (9) to calculate contrast values or contrast dif- ferences so as to characterize each of the situations shown in figure 4. First, let us consider the situations in which the effect of air pollution is perceptible against the sky, as shown in figures 4(a), (b), and (c). If the atmosphere is relatively hazy, the atmosphere along a horizontal line of sight is optically thick. In such a situation, for the case with- out a plume (=plume " 0), it can be shown that equation (9) reduces to equation (4) [see the asymptote in figure 2.(b)]. The contrast between the plume and the horizon sky background as observed at point Po is evaluated from equation (9) as follows: C - - Ih-plume - I plume Th (P - `a)plume exp(-Tplume) exp(-bextrp) (p W)background (10) Note that, depending on whether the product of the phase function and the al bedo (p w) for the plume or haze layer is larger or . smal 1 er than that for the background, the plume or haze layer will be brighter (C > 0) or darker (C < 0) than the background horizon sky. Also note that the con- trast is dependent on the plume optical thickness (Tplume); as Tplume approaches zero, Cplume approaches zero. Plume contrast also diminishes as the plume -observer distance increases. For the case in which the haze is homogeneous and optically thick, it can be shown that: 22 (pW)haze Chaze 1 (11) (p�)background These formulas can be used to evaluate impacts of the type shown in figures 4(a), (b), and (c). It should be noted, however, that in very clean areas where background conditions approach Rayleigh conditions, the assumption that the atmosphere along the horizontal line of sight is optically thick is no longer valid, and these formulas are only approxima- tions. In these situations, visibility model calculations are needed for more accurate solutions. To characterize the types of visibility impairment represented in figures 4(d) and (e), we need to calculate a change in sky/terrain con- trast caused by a plume or haze layer: aCr= Crlwith plume Cr1without plume where C , = It- 1 ume Ih- 1 ume rlwith plume h-plume C = IIh r t without plume I For simplicity we assume that the terrain that is viewed behind the plume has an intrinsic radiance, Iobj, which is a function of the horizon sky radiance Ih, namely, Iobj = (1 + CO)Ih. CO is the intrinsic con- trast. If the terrain were black, CO would equal -1. With this assump- tion we again use equation (9) to evaluate the following spectral radiance values: 23 It = Ih [1 + COexp(-bextro)1 It -plume = Ih-plume + C 0 1 h [exp(-b,,,.tr.)] [exP(-Tplume)] (12) The sky/terrain contrast values with and without the plume are: C = C exp(-b r ) riwithout plume 0 ext o I Cr - CQ-i----- [exp(-bextro) exp(- Plume) (13) 1with plume h-plume The change in contrast caused by the plume or haze is then: I AC = -CO exp(-bextro) 1 - (Ih-plume h exp(- T lume) (14} p It should be noted that the visual range and visual range reduction can be calculated from equations (12), (13), and (14). The visual range is defined as the distance ry from the observer to a black object such that the sky/target contrast Cr = -0.02 at a = 0.55 um. By solving equations (12), (13), and (14) for ro = ry such that Cr = -0.02, we can obtain the following formulas: r _ 3.912 (15) v0 - ext for a homogeneous atmosphere without a plume and . I ry - b1 3.912 - In h plu e - pl ume (16 ) ext h 24 The fractional visual range reduction is simply In Ih-plume + z ery (ry - rv0) - —ih plume - rv0 rv0 3.912 Further discussion of the relationships between plume optical thick- ness, extinction coefficient, visual range, and sky/terrain contrast is presented in appendix A. Equations (10) and (14) are the basic formulas upon which this work- book is based. Because of the assumptions previously noted, these equa- tions are approximate; more exact solutions can be obtained using the com- puter -based plume visibility model. Equations (10) through (14) can be used to determine contrasts at different wavelengths in the visible spectrum. This workbook describes how calculations can be made at a = 0.40, 0.55, and 0.70 um. The contrast at a = 0.55 um is used as an over- all indication of relative brightness of a plume or haze layer. The con- trasts at a = 0.40 and 0.70 on are used to determine the coloration of the plume or haze layer relative to the background. The blue -red ratio, indicative of coloration, is calculated from these contrast values as follows: 1 + C(a = 0.4 vm)plume R = + a = 0.7 urn (18 ) plume The visibility model uses many parameters to characterize plume visual impact; however, the following four parameters are particularly important: > Visual range reduction [see equation (17)] 25 > Plume blue -red ratio [see equation (18)] > Plume contrast [see equation (10)] > Plume perceptibility parameter DE(L*a*b*). We have already described the first three parameters. The fourth parameter, the plume perceptibility eE value, characterizes the extent of color difference between the plume and a viewing background. Whereas visual range reduction and plume contrast values are calculated at one wavelength ( a = 0.55 vm) and blue -red ratio at two wavelengths ( a = 0.4 and 0.7 um), the eE value is calculated across the visible spectrum (0.4 < a < 0.7 vm) . The DE parameter is particularly useful to charac- terize plume perceptibility because it is a function of the difference in coloration between the plume and a viewing background in terms of both brightness difference and color (chromaticity) difference. Because the spectral radiances [I(a)] have to be calculated at several wavelengths to determine AE, the of parameter is not appropriate for use in hand calcula- tions. We are not aware of any studies that have specifically addressed the question of what the standards for visibility impairment should be in terms of these quantitative specifications. A very well defined, rea- sonably large target, with sharp edges that contrast with a viewing back- ground, probably has a threshold of detectability corresponding to a con- trast of t0.02 and a OE value of about 1. Figure 4 shows the five basic viewing situations in which air pollution might be visually perceptible. A direct comparison of two adjacent colors is only possible when the plume or haze layer contrasts with a viewing background. In most situations, however, the boundary between a plume and a viewing background is not distinct, but diffused, because of the nature of plume dispersion. This is particularly true at large distances from the emissions source. A general haze can only be detected by comparison with the memory of clearer conditions on previous days. Thus, there is no clear set of threshold values to characterize visibility impairment. The situation is made even more complicated by the fact that the W magnitude of visual impact caused in a class I area by a given emissions source varies significantly over the course of a year. Although impacts may be visible during the worst day in a year, they may not be visible most of the year. For this workbook, we have adopted the following criteria for use in level-1 and -2 tests. If the absolute value of either plume contrast (Cplume) or the change in sky/terrain contrast (ACd is greater than 0.1, or if plume eE(L*a*b*) is greater than 4 for the worst - day impact case, then the possibility that the visual impact would be judged adverse or significant cannot be ruled out. 2.2 PLUME -OBSERVER GEOMETRY Figures 5 and 6 show plan and elevation views, respectively, of an arbitrary plume -observer geometry defined by elevation angle B, the hori- zontal angle a between the line of sight and the plume centerline, the distance x downwind from the emissions source of the plume parcel being observed, and the distance rp from the observer to this plume parcel. Although the visibility model offers the option of specifying any arbitrary angle B, for most real -world problems B e 0 since plumes are usually not observed at close range. Thus, for the sake of simplicity, the formulas presented in this workbook are based on the assumption that the line of sight is horizontal (6 = 0). In the previous section we showed that plume visual effects are dependent on the plume optical -thickness T. which is proportional to the integrals of NO2 and particle concentrations along the line of sight. For a horizontal line of sight (B = 0) through a Gaussian plume, these integrals can be calculated using the following approximate formulas. For a fixed plume orientation and observer location, as shown in figure S. the magnitude of plume optical thickness (T) in equations (10) and (14) is a function of the direction of view (i.e., the angle a). Although the optical thickness T of the plume is a minimum at a = 900, the Plume -observer distance rp is at its minimum value also since l 27 me x `—PLUME EMISSIONS SOURCE Figure 5. LINE OF SIGHT wp— p min / r P OBSERVER Plan view of observer -plume geometry. 28 Figure 6. Elevation view of observer -plume geometry. 29 rpa ' rp-min sin a Thus, there are two counterbalancing effects of a. Although the optical thickness of the plume is larger for small as, the distance between the plume and the observer is larger, the magnitude of plume effects is correspondingly smaller, and the apparent size of the plume is smaller. In very clear background areas, if the observer is close to the source, impact magnitudes will be largest for lines of sight with small as, though the plume will appear smaller as noted above. However, in most situations visual effects are maximum or close to maximum when the line of sight is perpendicular to the plume (a = 90°) such that rp = rp_min- Because of this, we recommend, for this workbook, that plume effects be evaluated for lines of sight perpendicular to the plume centerline. The optical thickness of a plume is proportional to x dy = Q exp _, H Q z 2 (27r) 1/2 azu sin a z +eXp _1 -z2(.H Qz (19) For lines of sight directly through the center of a Gaussian plume, we have simply x dy = 1/2 Q (20 ) (27r) vzu sin a When the plume is uniformly mixed in the vertical between the ground and an elevated stable layer of height, Hm, we have 30 m X dy - H mu sin a _m (21) Note that these formulas no longer apply as a approaches 0. If the observer were within the plume, the integral along the plume centerline (a = 0*) would have to be calculated numerically from the Gaussian equation. As we discuss in a later subsection of this section, the proba- bility of an observer's being within the plume is exceedingly small, so that a quite adequate general description of plume -observer geometry is as shown in figure 5 (i.e., lines of sight oblique to the plume centerline). It should be understood from the foregoing discussion that visual impacts are a function of the following parameters: > NO2 and aerosol plume loading (Q) > Wind speed (u) > Vertical extent of plume mixing (aZ or Hm.) > Distance between the plume and observer (rp) > Background extinction coefficient (bext)- Thus, the visual impacts will increase with: > Increasing NOx, particulate, and aerosol precursor emis- sion rates. > Increasing NO2 and aerosol formation rates in the atmos- phere from precursors. > Decreasing wind speed. > Decreasing vertical mixing. > Decreasing plume -observer distance (i.e., the wind direc- tion is such that plume transport is toward the observer). > Increasing background visual range (i.e., decreasing -extinction coefficient, the lower bound being the Rayleigh scattering coefficient of particle -free air). 31 The largest visual impacts for a given emissions source and observer location (in a class I area) occur when a plume is transported relatively close to the observer, with light winds and little vertical mixing. Thus, to estimate worst -case impacts, it is necessary to identify reasonable worst -case meteorological conditions such as light -wind, stable condi- tions; light -wind, limited -mixing conditions; and stagnation conditions. These worst -case conditions are dependent on meteorological conditions in the area and the distance between the emissions source and the class I area. For example, although an F stability and a 1 m/s wind speed may be reasonable worst -case conditions for visual impacts close to a source, they certainly are not for observer locations 100 to 200 km from the source. At 1 m/s, it would require 28 to 56 hours for a plume to be transported 100 to 200 km. Typically, stable (F stability) conditions would not be likely to persist for more than 12 hours.* If we assume that a stable plume would remain intact for no longer than 12 hours, the worst - case wind speeds for the observer locations 100 and 200 km from the emis- sions source would be 2.3 and 4.6 m/s, respectively. In this workbook we use this assumption regarding persistence of stable conditions. Another consideration is that of variability in wind speed and wind direction, and of its impact on plume dispersion and transport to within view of an observer in a class I area. The location of a plume parcel relative to the emissions source at any time tf is dependent on the spatially- and temporally -varying windfield, the time of emission from the source t0, and the transport time At = tf - to: tf r = v(x,y,z,t) dt (22) t0 * It should be noted that, during winter or at high latitudes, stable conditions (E or F stability) could persist longer than 12 hours. The analyst may wish to use a different assumption regarding persistence if appropriate to a given application. 32 If the displacement vector r is within a given radius of the observer point in a class I area, one might expect a visual impact, depending on the dilution of the plume parcel. Thus, we could have transport from the emissions source to the observer locations in any number of possible trajectories, as shown by the examples in figure 7. If one had a set of spatially- and temporally -resolved wind data, one could perform the vector integration shown in equation (22) and determine the frequency of occur- rence of transport toward a class I area. Usually, however, wind data are not available for more than one location in a region, and one must make assumptions regarding the variability of wind in time and space. Uncertainty in the meteorological conditions used for input is probably the most important source of error in visibility impact calcula- tions. The level of sophistication of an air quality or visibility impact analysis is most often limited, not by theoretical or analytic concerns, but by the lack of a detailed meteorological data base for the region of interest, with spatial and temporal resolution appropriate for the task. The level-1 visibility screening analysis is based on assumptions regarding worst -case meteorological conditions. The level-2 visibility screening analysis is based on the assumption that the joint frequency of occurrence of meteorological conditions, at plume height, at a point within a region, is representative of all points within the region. It is also assumed that plume geometry can be approximated by a straight plume trajectory, as shown by trajectory 1 in figure 7. This assumption will be conservative in most situations (i.e., overestimate impacts). However, in other situations, such as during a stagnation condition in a valley, the assumption may cause underestimation of impacts because wind reversals could cause a buildup of emissions as shown by trajectory 2 in figure 7_ For level-3 analyses more detailed representations of the windfield could be used as the basis for visibility impact calculations, depending on the availability of meteorological data. 33 2.3 CHARACTERIZING THE FREQUENCY DISTRIBUTION OF PLUME VISIBILITY IMPACTS In this workbook, the purpose of level-1 and -2 screening analyses is to estimate the worst -case visual impacts that might occur on about one day per year. For the level-3 analysis, the frequency of occurrence of impact of different magnitudes can be calculated, as well as the worst -day impacts. It is important to determine the frequency of occurrence of visual impact, because the adversity or significance of impact is dependent on how frequently an impact of a given magnitude occurs. For example, if a plume is perceptible from a class I area a third of the time, the impact would be considered much more significant than if it were perceptible only one day per year. The assessment of frequency of occur- rence of impact should be an integral part of a visibility impact assess- ment. In this subsection we discuss how one can determine both the magni- tude and frequency of occurrence of visual impact. This procedure entails making several model runs for different values of the following important input parameters: > Emission rates (particulate, S029 NOx). > Wind speed. > Wind direction. > Atmospheric stability. > Mixing depth. > Background ozone concentration. > Background visual range. > Time of day and season. > Orientation of observer, plume, and sun. > Viewing background (whether it is sky, cloud, or snow- covered, sunlit, or shaded terrain). Because of the large number of variables important to a visual impact 35 calculation, several calculations are needed to assess the magnitude and frequency of occurrence of visual impact. It is recommended that a computer model be used for level-3 analysis because of the large number of scenarios and calculations involved. It would be ideal to calculate hourly impacts over the course of a year or more using hourly values of the above variables. However, such an extensive data base is rarely available for use. Even if it were available, the computing costs involved would be prohibitive. It is therefore preferable to select a few representative, discrete values for each of these variables to represent the range (i.e., the magnitude and frequency of occurrence) of visual impact over a given period of time, such as a season or year. One can start with conditions that cause the worst impacts and then assess the frequency of occurrence, in a season or year, of all the variables having worst -case values simultaneously. It is possible to imagine a worst -case impact condition that would never occur in the real atmosphere; this condition could be represented on a cumulative frequency plot, such as that of figure 8, as point A. The impact is great, but it almost never occurs. If another worst -case situa- tion less extreme than point A were selected, the magnitude of impact would be less, but it might occur with some nonzero frequency, about one day per year, for example (the reasonable worst -case impacts for level-2 and level-2 analyses). It is possible to select various values of all the important input variables and to assess the frequency with which those conditions resulting in impacts worse than a given impact would occur. By this pro:ess, several points necessary to specify the frequency distribu- tion could be obtained (for example, points B. C. and D in figure 8). With average (50-percentile) conditions, a negligible impact, as shown at point E in figure 8, might be found. In figure 8, the ordinate could be any of the parameters used to characterize visibility impairment, such as visual range reduction, plume contrast, blue -red ratio, or tE, and the abscissa could represent cumulative frequency over a season or a year. In a visual impact assessment, it is recommended that one select various combinations of upper -air wind speed, wind direction, and atmos- 36 L a� +-J a E �o L 0. i-) L) f0 Q E rr 19 E 0 25 50 75 100 Cumulative Frequency of Occurrence (%) Figure 8. Example of a frequency distribution of visual impact. 37 pheric stability; background ozone concentration; and background visual range to specify the frequency distribution of visual impact. If one has a large, concurrent data base of all five of these variables, it would be desirable to calculate a five -way joint -probability distribution matrix and to use these joint probabilities to calculate frequency of occurrence of impact. However, in most situations, such a data base is not available, and one must treat the various worst -case events as independent probabilities. With this assumption, the probability of worst -case impacts can be calculated by multiplying the independent probabilities. This can be represented as follows: f(y > y') = n f(xi > xi') i where f(y > y') is the cumulative frequency of impact y greater than y', and f(xi > xi') is the cumulative frequency of variable xi having values that would cause greater impact than the value xi'. In such an application, one might obtain an estimate of cumulative frequency by using the joint frequency distribution of upper -air wind speed and wind direction and the separate frequency distributions of upper -air stability, ozone concentration, and visual range. For example, the plume perceptibility parameter aE has a cumulative frequency distribu- tion that can be estimated as follows: where f(aE> DE') =f(u<u', WD<WD') -f(s> s') • f([03] > 103]') f(ry > rv') f(nE > oE' ) = the frequency of occurrence of eE values greater than AE'. AP is calculated on the basis of a wind speed u', wind direc- tion WD', stability s', ozone concentra- tion 1031', and visual range rv'. f(u < u', WD < WD') = the frequency of occurrence of wind speeds L RE., less than u' associated within a specified value (WD') of the worst -case wind direc- tion. f(s > s') = the frequency of occurrence of stabilities greater than s'. f(1031 > 1031') = the frequency of occurrence of background ozone concentrations greater than [03]'. f(ry > rv') = the frequency of occurrence of background visual range values greater than rv'. Each of the input parameters that are important to the visibility model calculation varies significantly over the period of a year, and all are discussed in the following paragraphs. 2.3.1 Wind Speed Wind speed affects plume visual impact strongly because plume center- line concentrations and plume line -of -sight integrals are inversely pro- portional to wind speed. Greater impact would be expected during light - wind stagnation conditions than during strong -wind, well -ventilated condi- tions. Also, since the age of a plume parcel at a given distance downwind from a power plant is inversely proportional to wind speed, more time is available at low wind speeds for the chemical conversion of primary emis- sions. A well -aged plume parcel is more likely to cause a reduction in visual range than is a younger one. However, the time necessary to trans- port emissions a given distance toward a class I area increases with decreasing wind speed. Thus, during light -wind conditions, several hours of persistent conditions may be needed to transport emissions to a class I area where they could cause visual impact. 2.3.2 Wind Direction Wind direction also affects plume visual impact, because the direc- tion of plume parcel transport affects the orientation of the plume with respect to the observer. If the plume is transported directly toward an 39 observer, the observer's line of sight directly along the center of the plume is significantly affected. As noted previously, if the observer's line of sight is oblique to or along the plume axis, plume optical thick- ness will be greater than if the line of sight is normal to the plume axis. However, there is a compensating effect; the direction of plume transport affects the distance (rp) between the observer and the plume material. Plume discoloration is..diminished by light scattered by the intervening, or background, atmosphere. The more distant the plume material, the less colored and less perceptible it is likely to be. This decrease in plume coloration can be expressed as follows: where Cplume (rp) Cplume (0)exp(-3.9 rp/rv0) , (23) Cplume(r)9 Cplume(0) = plume contrasts at plume -observer distances r and 0, respectively. rp = plume -observer distance. rv0 = background visual range. It should be noted that visual range reduction does not decrease with increasing distance between the plume and the observer, assuming one can still see across the plume. However, the aesthetic effects of this visual range reduction would be less, since contrast reduction (eCd would decrease exponentially, as the plume -object distance increases as shown in equation (14). Also, it should be noted that with a more distant plume, only the contrast of distant terrain objects would be affected and fewer lines of sight would be impacted. In addition, the aesthetic impact caused by plume discoloration is likely to be less if the plume is farther away, because the plume will appear smaller (i.e., fewer lines of sight will be affected). To illustrate the effect of wind direction, figure 9(a and b) shows the positions of two plumes from a hypothetical emissions source relative to a vista in a class I area 90 km away. Plume t2 oy outlines are shown 40 VA (a) Worst —Case Wind Direction Figure 9. Schematic diagram showing plume -observer geometry for two wind directions. 41 0 (b) Wind direction resulting in less impact than the worst case. Figure 9 (Concluded) 42 to scale with cry values appropriate for a Pasquill E stability. Of course, actual plume trajectories would be affected by wind channeling, complex terrain, and changes in wind direction with time, so these figures are only idealized representations. Figure 9 shows trajectories that could occur with north -northwesterly and north -northeasterly winds. A plume associated with a north -northeasterly wind direction (defined by a sector 22.5° wide) could be anywhere within the extremes of the sector shown in figure 9. Thus, a wide range of impacts could occur associated with north -northeasterly winds. The worst case would be that shown in figure 9(a), in which the plume is transported directly toward the obser- ver. Of course, the worst -case conditions of figure 9(a) would occur for only some of the periods of north -northeasterly flow. Figure 9(b) shows that, for another wind direction, plume discoloration would be consider- ably less, because plumes would be tens of kilometers away from the observer, and the observer's line of sight could be nearly perpendicular to the plume, not along the plume as in figure 9(a). Since the case shown in figure 9(a) is not a likely occurrence, the level-1 and level-2 analyses are not suitable for evaluating the visual impact associated with this plume -observer orientation. A level-3 analysis is required when views along the plume axis are of concern. 2.3.3 Atmospheric Stability Upper -air stability controls the rate at which source emissions are mixed with ambient air. During stable conditions, diffusion is limited, particularly in the vertical direction, so plumes remain as ribbon-like layers. Plume discoloration is most apparent during such stable condi- tions, because the integral of NO2 and particulate concentrations along the line of sight is greater. During well -mixed' (neutral or unstable) conditions, plumes are rapidly diffused and not likely to be visible as plumes per se. Stability, or the rate of plume mixing, also has an effect on chemical conversion within a plume. The conversion of nitric oxide (NO) to nitrogen dioxide (NO2) is diffusion -limited in stable plumes, as is the 43 formation of sulfate and nitrate, because background ozone that effects NO2 formation is depleted within the plume. 2.3.4 Background Ozone Concentration An important input parameter to the visibility model is the back- ground ozone concentration, that is, the concentration of ozone outside the plume. Ozone reacts directly with the colorless nitric oxide emitted from power plants to form the brownish gas, nitrogen dioxide, the princi- pal plume colorant: NO+03 +NO2+02 Ozone is also indirectly important in the oxidation of plume NO2 and S02, since ultraviolet radiation photolyzes ozone to form the hydroxyl radical (OH-) that reacts with NO2 and S02 to form nitric acid and sulfate aero- sol. Calculations should be made for the median (50-percentile) background ozone concentration as a minimum and possibly for the 25- and 75- percentiles also. 2.3.5 Background Visual Range Background visual range is also an important input parameter, because the magnitude of plume discoloration visible from a given location depends on the clarity of the intervening atmosphere. Plume discoloration is much more noticeable in the extremely clear areas of the Southwest, for example, than in hazy areas. Equation (23) shows that as the background visual range (rv0) decreases (i.e., the atmosphere becomes hazier), the degree of plume discoloration decreases also. Thus, one must supply one or more (e.g., 25-, 50-, and 75-percentile) values of background visual range in the study area to characterize impacts for different levels of atmospheric clarity. 44 2.3.6 Study Area Topography The topography of an area also has an influence on visibility impair- ment. High terrain affects the transport of emissions, particularly dur- ing worst -case stable conditions. It is likely that a stable plume would be channeled by high terrain and remain in a valley. Thus, the assumption of a straight plume trajectory approaching an observer location on ele- vated terrain, such as is shown in figure 9(a), may never occur in some areas. The topography also affects the rate of dilution of plumes, with mechanically induced turbulence enhancing plume dilution. Topography also affects the views from a given vista location. For example, topography can obstruct views in certain directions from a vista where plume material is located. It can also have an effect on the type of viewing background (what is visible behind the plume), which has an effect on plume discoloration. 2.3.7 Season and Time of Day Gas -to -particle conversion is also a function of season and time of day, with higher conversion rates at times when ultraviolet flux is great- est. Also, the sun angles (i.e., azimuth, zenith, and scattering angles) are dependent on season and time of day. 2.3.8 Model Runs If one used all the permutations of the important input variables, one could make hundreds of plume visibility model runs to characterize the frequency distribution of visual impact over a season or a year. For example, if 5 wind directions, 3 wind speeds, 2 stabilities, 3 background visual ranges, 3 background ozone concentrations, and 2 seasons are evalu- ated, one would have to make 540 runs (5 x 3 x 2 x 3 x 3 x 2). Further- more, if 10 downwind distances were evaluated and 4 viewing background colorations were considered for each line -of -sight geometry, a total of 219600 individual line -of -sight calculations would be needed. The comput- 45 ing costs for this many calculations would be prohibitive. To reduce costs, one can reasonably approximate the frequency distribution of impacts by using median values of background ozone concentrations and visual range and evaluating impacts for sun angles corresponding to one season (e.g., spring or fall), thus reducing the total number of runs in this example to 30. 46 3 LEVEL-1 VISIBILITY SCREENING ANALYSIS The level-1 visibility screening analysis is a simple, straightfor- ward calculation designed to identify those emissions sources that have little potential of adversely affecting visibility in a class I area. If a source passes this first screening test, it would not be likely to cause adverse visibility impairment, and further analysis of potential visi- bility impacts would be unnecessary. If the source fails this test, addi- tional screening analysis would be needed to assess potential impacts. The level-1 visibility screening analysis requires a minimal amount of information about the source and only a few minutes of an analyst's time to evaluate potential visibility impairment. The input parameters heeded to evaluate potential visibility impacts with this screening analy- sis procedure are as follows: > Minimum distance of the emissions source from a poten- tially affected class I area (in kilometers). > Location of the emissions source and class I area. > Particulate emission rate (in metric tons/day). > NOx emission rate (in metric tons/day). > S02 emission rate (in metric tons/day). 3.1 DERIVATION OF LEVEL-1 SCREENING ANALYSIS The level-1 visibility screening analysis is designed to evaluate two potential types of visibility impairment that can be caused by plumes from emissions sources. These two types of visibility impairment are caused by nitrogen oxide, particulate, and sulfur dioxide emissions. Figures 10 and 11 illustrate the two types of plume impacts. One is a discolored, dark 47 -r r_ 1_ A - 1. V -1 - .I A SKY —1-1 BACKGROUND Figure.10. Two types of plume visibility impairment considered in -.the level-1 visibility screening analysis. BLACK TARGET OR~ HORIZON SKY VIEW- ING BACKGROUND EMISSIONS SOURCE PLUME AND SECTOR CENTERLINE ::.::.• 22.5° SECTOR ~1` •'•'•�' OBSERVER'S LINE OF SIGHT (PERPENDICULAR TO PLUME OBSERVER CENTERLINE) AT DOWNWIND DISTANCE X Figure 11. Geometry of plume, observer, and line of sight used in level-1 visibility screening analysis, 9.1 plume observed against a bright horizon sky (labeled 1 in figure 10). This effect is caused principally by NO2 gas formed from NOx emissions, though particulates can contribute in some cases. The other type is a bright plume observed against a dark terrain viewing background (labeled 2 in figure 10). This effect is caused principally by particle emissions and sulfate aerosol formed from S02 emissions. Model calculations (Latimer et al., 1980a) suggest that sulfate aerosol does not form in stable plumes containing a significant amount of NOx. Sulfate formation does not occur until emissions are diluted sig- nificantly with background air. However, the visual impacts caused by NOx and particulate emissions are greatest when the plume material is concen- trated, as in light -wind, stable conditions. For these reasons, we con- sider two different meteorological conditions: > For maximum impact caused by particulate and NOx emis- sions: stable (Pasquill-Gifford stability category F), light -wind conditions with a 12-hour transport time to the closest class I area. > For maximum impact caused by S02 emissions: limited mixing conditions, vertically well -mixed plume within a 1000 m mixing depth, 2 m/s wind speed. For both cases, the geometry of the plume, observer, and line of sight assumed for this screening analysis is shown in figure 11. The plume is assumed to pass very close to the observer, with its centerline half the width of a 22.5' sector away from the observer at the given down- wind distance x. The observer's line of sight is assumed to be perpen- dicular to the plume centerline. The viewing background is assumed to be either the horizon sky or a black terrain object located on the opposite side of the plume a distance equivalent to a full sector from the observer. . J 3.1.1 Impacts of Particulate and NOX Emissions Meteorological conditions are assumed to be stable with light winds. Pasqui 11 -Gifford F stability is used to characterize the vertical dispersion (oz) important in evaluating the visual impacts for horizontal lines of sight. Since such stable conditions are not likely to persist for more than 12 hours in a typical diurnal cycle, we selected a worst - case wind speed that would transport emissions from the source to a class I area in 12 hours. Thus, wind speed is determined as a function of distance x to the class I area as shown below: u = (x km)(1000 m/km) - 2,31 - 10-2(x) m/s (12 hr 0 sec/Fr Thus, a 2.3 m/s wind would be used to evaluate impacts in a class I area 100 km from the emissions source. The horizontal optical thickness through the center of an elevated stable plume is T = (2w) 2Qzu where Q is the mass emission rate of NOX and particles multiplied by the respective light absorption and scattering efficiencies of these two species. For the level-1 analysis we conservatively assume that there is complete conversion of NOX emissions to NO2 in the atmosphere. We can calculate the absorption 002) and scattering (particle) com- ponents of the plume optical thickness separately, as follows: 50 'NO = babs/(ug/m3) P QNO 2 2 Tpart $ bscat/(ug/m3) P Qpart ' where p= 1 (2w) 2ozu The value of p is evaluated so that the units of Qpart and QN02 in the above formulas are in metric tons per day: p = (1012 in/metric ton)(day/24 hr)(hr/3 (2s)1/2(oz)(2.31 x 10-2)(x) = 2.0 - 108 Qzx The absorption per unit mass of NO2 is calculated for a wavelength of 0.55 um as follows (Dixon, 1940): babs/( ug/m3) _ (0.31 km-1/arxnL = 1.65 x 10-7m-1/(ug/m3) • (1881 ug/m3/ppm)(1000 m/km) The scattering coefficient per unit mass of aerosol for a wavelength of 0.55 tm was calculated using Mie scattering theory. A primary particle size distribution typical of a coal-fired power plant equipped -with an electrostatic precipitator (Schulz, Engdahl, and Frankenberg, 1475) was assumed. This distribution has a mass median diameter of 2 um, a geomet- ric standard deviation of 2, and a density of 2.5 g/cm3. For such a size distribution: 51 bscat /(u9/m3) = 10 - 10-7m-1/ ( ug/m3) We can use equation (10) from chapter 2 to evaluate the sky/plume contrast resulting from NO2 light absorption. For this level-1 analysis, we assume that the phase functions for the plume and the background atmos- phere are equal. With this assumption, equation (10) reduces to the following equation: 'NO2 plume "Part + TNO 1 - exp - part TNO exp -3.912 rp/rv0 2 where rp = the observer -plume distance, which, for the geometry shown in figure 11, 0 = x tan(.222.5 = 0.199 x , 2 rvO = background visual range (km), = NO2 and particulate components of plume optical TN02' Tpart thickness, as discussed above. It should be noted that this equation can be simplified (valid only for small plume optical thicknesses, T < 0.1) by using the first two terms of a series expansion of the second term: plume - - TNO 2 exp(-3.912 rp/rvO) From this approximate formula we see that the sky/plume contrast is proportional to the plume NO2 line -of -sight integral (TN02) and decreases as the plume -observer distance increases. 52 Now let us consider the reduction in sky/terrain contrast by the same plumd. If the background terrain is black, then Co = -1, and we can rewrite equation (14) as follows: AC r 1 - 1 + exp - Tpart zNO2)] exp(-3.912 ro/rv0) Cplume 1 where Cplume is as defined above, and ro is the observer -object distance, which, for the geometry shown in figure 11, equals 2 - x - tan (22.5 /2), where x is the downwind distance from the emissions source to the class I area. 3.1.2 Impacts of S02 Emissions We evaluate the worst -case impacts of S02 emissions, assuming a mul- tiday stagnation episode (limited mixing). Both primary particle emis- sions and sulfate (SO4n) aerosol formed in the atmosphere from S02 emis- sions reduce the contrast of objects viewed through the plume. However, NOx emissions are converted to nitric acid vapor by reaction with the hydroxyl radical, the same species responsible for conversion of S02 to S040. Hence, no NO2 is assumed to be present. Since sulfate forms slowly in the atmosphere, the maximum impact does not necessarily occur at the class I area closest to the emissions source. Thus, for the level-1 analysis we evaluate sulfate impacts at a distance of 350 km from the source, the equivalent of two days' transport time from the emissions source for an assumed 2 m/s wind speed. Further- more, we evaluate the sky/terrain contrast reduction of a terrain feature located one-fourth the background visual range distance. The contrast reduction of a terrain feature at this distance is a maximum for a given increase -in extinction coefficient (see appendix A). Note that the plume itself would not be visible, but plume material uniformly diffused through the mixed layer could cause a reduction in sky/terrain contrast. 53 The sulfate mass flux at any given distance downwind is calculated by solving the following differential equations: where dQSO2 = - + —�- ( kf kd )QSO 2 dQSO4= -- t = 1.5 kf QS02 ' QS02� QSO4= =mass flux of S02 and SO4% respectively, in the plume at downwind distance corresponding to transit time t, kd = rate of S02 loss due to surface deposition vd = Hm kf = rate of S02-to-SO4= conversion , vd = deposition velocity , Hm = mixing depth. The solution to these equations is 15 QSOC ` kf ` . +` f QS02 1 - expC (-k f + kd) t1 For an assumed transit time of 48 hours, mixing depth Hm of 1000 m, S02 deposition velocity (diurnal average) vd of 0.5 cm/s, and S02-to-SO4= conversion rate (diurnal average) kf of 0.5 percent/hr, we find that the. sulfate mass flux is: QSO4 = 0.218 QS02 54 We assume an average scattering coefficient per unit mass concentra- tion of sulfate and primary particles of 6 x 10-6 and 1 x 10-6m 1/(Vg/m3), respectively, appropriate for typical size distributions (see Latimer et al., 1978, and Schulz, Engdahl, and Frankenberg, 1975). The optical thickness due to total aerosol for this limited mixing case is then simply: Apart + 1.31 QS02 j0-6m-1/Ug/m3)' `aerosol u Hm Now if we substitute the appropriate values of u and Hm, and the appropriate conversion factor from metric tons per day to ug/s, we have the following expression: Taerosol = (5.79 - 10-3) (Qpart + 1.31 QS02) . This is the total optical depth across a plume at a downwind distance of 350 km (transit time = 48 hr). We wish to use the optical depth between the observer and a terrain feature at the most sensitive distance, ro = rv0/3.912, as shown in appendix A. Thus, we must correct Taerosol accordingly. We assume the plume is uniformly mixed within a 22.5' sector, which is quite wide 350 km downwind: 0 2(x)tan 2225 = 2(350 km)(0.199) = 139 km The ratio of the optical depth between the observer and the most sen- sitive terrain feature to the total optical depth is then ry_ 545 km 55 Thus, we end up with the following expression: (1.06 x 10-5)(rv0)�Q art + 1.31 QSOaerosol ' 2 where rvO is the background visual range in km, and Qpart and QS02 are particle and S02 emission rates in metric tons per day. Substituting this optical thickness into equation (14) and assuming that Cplume - 0, we have the following expression for the contrast reduc- tion caused by sulfate aerosol and particulate emissions during a stagna- tion episode: AC = 0.368[1 - exp(- aerosol)] ' 3.2 INSTRUCTIONS FOR LEVEL-1 SCREENING ANALYSIS The level-1 screening procedure comprises these steps: > Determine the minimum, straight-line distance x, in kilo- meters, between the emissions source and the closest boundary of a class I area. Determine cZ corresponding to this distance for Pasquill-Gifford F stability from figure 12 (Turner, 1969). If x > 100 km, set oZ = 100 m. Compute the plume dispersion parameter p as follows: p = 2.0 - 108 a1 x * Throughout this workbook, formulas used in the level-1 or level-2 analysis procedure are indicated with a prefix p (for procedure). Those equations that are not part of a screening procedure are either not numbered or not labeled with the p prefix. 56 ;5000 4000 3000 M 1000 500 400 300 200 H L E 18 70 TON 60 50 40 30 0 20 10 r B F 0.1 0.2 0.5 1 2 3 4 5 10 15 20 30 40 50 Distance Downwind (km) Source: Turner 0969). Figure 12. Vertical dispersion coefficient (oz) as a function of downwind distance from the source 57 ..-1 where oZ is in meters and x is in kilometers. > From the total mass emission rates of particulates (Apart) and nitrogen oxides as NO2 ONO ) in metric tons per day, calculate the following opticalxthicknesses: part = 10 - 10-7 P Qpart (P-2) TN0 2 = 1.7 - 10 7 P QNO (P-3) x > Determine locations of the emissions source and the class I area on the map shown in figure 13 and the appro- priate value, rv0, of the background visual range in kilo- meters.* If the emissions source and class I area are in different visibility regions, use the larger value of rv0 in subsequent calculations. > Calculate the following optical thickness parameter for primary and secondary aerosol: 'aerosol = (1.06 x 10-5)(rv0) Qpart + 1.31 QSO 2. (p-4) > Calculate the following contrast parameters (note that Cl is plume contrast against the sky, C2 is plume contrast against terrain, and C3 is a change in sky/terrain contrast caused by primary and secondary aerosol): * The values of rv0 shown in figure 13 are estimated mean visual ranges in kilometers at 0.55 un based on the work of Tri jonis and Shapland (1979). Their values, based on human observation of terrain features at National Weather Service meteorological stations, have been increased by 50 percent to agree with mean visual range measurements made in the Southwest (Malm et al., 1979) using a telephotometer equipped with a narrow band filter at 0.55 um. This correction was made because it is believed that the telephotometer provides more accurate measurements of visual range than those produced by human observation. tNO2 C1 _ T + T 1 - exp (-tpart TNO [exp(-0.78 x/rv0) part NO2 \ 2)] (P-5) C2 = 1 - -r exp -Tpart - TNO exp(-1 .56 x/rv0) ' 1 2 (p-6) C3 = 0.368 [1 - exp(- Taerosol)] (p-7) > If the absolute value of C1. C2, or C3 is greater than 0.10, the emissions source fails the level-1 visibility screening test, and further screening analysis is required to assess potential visibility impairment. If the abso- lute values of C1, C2, and C3 are all less than 0.10, it is highly unlikely that the emissions source would cause adverse visibility impairment in class I areas; therefore, further analysis of potential visibility impacts would be unnecessary. * This screening procedure could be used as an aid in siting studies. The distance xmin could be determined so that the criteria for C1 and C2 would be met on the basis of a given regional background visual range and NOX and particulate emissions rates. The industrial planner could use this xmin distance as a factor in his siting analysis. If the preferred site were at a distance x < xmin from a class I area, further analysis (level-2 and possibly level-3) of potential visibility impacts would be needed to evaluate the acceptability of the site. .0 3.3 EXAMPLE APPLICATIONS OF THE LEVEL-1 ANALYSIS 3.3.1 Example 1 Suppose we evaluate a hypothetical, large power plant located 100 km from -a class I area in southern Utah. The power plant emits 10 metric 'tons per day of particulates, 100 metric tons per day of NOx (as NO2), and 200 metric tons per day of S02. For x = 100 km, the Pasquill-Gifford stability class F, oZ = 90 m. Thus, we calculate the following values: 8 p = (90)(100) 2.22 x 104 Is Tpart = (10 x 10-7)(2.22 x 104)(10) = 0.222 , TN02 = (1.7 x 10-7)(2.22 x 104)(100) - 0.378 From figure 13 we see that the background visual range for southern Utah is 170 km. We calculate the following parameters: Taerosol = (1.06 • 10-5)(170)(10 + 1.31 200) - 0.490 , C1 _ Q.378 [1 - exp(-0.222 - 0.378)][exp(-0.78 100/170)] 0.222 + 0.378 _ -0.180 , 61 ICz k / = 1 - 11�181 Jexp(-0.222 - 0.378)I [exp(-1.56 100/17� = 0.132 , C3 = 0.368 [1 - exp(-0.490)] = 0.143 Since the absolute value of each of these contrast parameters (Cl. C2, and C3) is greater than 0.10, we cannot rule out the possibility that this hypothetical power plant would cause adverse or significant visi- bility impairment in the class I area. This is not to say that the source actually does cause such impact. It means only that it does not pass the level-1 screening test. Further level-2 or level-3 analysis may show that the visual impact is not significant or adverse. The reader can verify that if this power plant were sited at least 150 km from a class I area in the same region, it would pass the first two tests (i.e., IC11 < 0.10 and IC21 < 0.10); however, it would still fail the third level-1 test (C3 = 0.143 > 0.10). The reader can also show that if the same plant were sited in a region with 40 km visual range at the same distance (100 km), it would easily pass the level-1 screening tests. Indeed, in such a region the source could be located as close as 70 km and still pass the level-1 tests. Let us return to our original example and consider whether the source could meet the level-1 tests by cutting particulate and S02 emissions in half. By doing this, the reader can verify that, though C2 is reduced from 0.132 to 0.097, and C3 is reduced from 0.143 to 0.080, IC11 actually is increased from 0.180 to 0.189. Thus, even with particulate and S02 controls; the source would not meet the level-1 C1 test. In order to do so, NOx emissions would have to be reduced or the plant would have to be sited about 150 km away from the class I area. 62 It is interesting to note that iC11 is best reduced by NOx emissions control, IC21 is best reduced by particulate emissions control, and IC31 is best reduced by S02 emissions control. Only iC11 and 1C21 can be reduced by increasing the distance between the site and the class I area. 3.3.2 Example 2 -Consider the impact of a proposed plant that would emit 20 metric tons per day of particulate matter and no NOx or SO2, and would be sited 50 km from a class I area in southern Arizona. We calculate the following parameters: p 2(08)(50) 8 = 5.13 104 Tpart = (10 • 10-7)(5.13 • 104)(20) = 1.03 , TNO2 = 0 , We see from the map shown in figure 13 that the background visual range (rvO) in southern Arizona is 110 km. Taerosol = (1906 • 10-5)(110)(20 + 1.31 - 0) = 2.33 - 10-2 , Now we calculate the contrast parameters: Cl = - --- 0 ---- [1 - exp(-1.03 - 0)][exp(-0.78 • 50/110)] = 0 , 1.03 + 0 63 C2 = [J..- ll + O/ exp(-1.03 - 0) [exp(-1.56 - 50/110)] = 0.316 , C3 = 0.368 [1 - exp(-0.0233)] = 0.008 Since C2 is greater than 0.10, there is a potential for visibility impairment in the class I area, and further screening analysis (level-2 or level-3) would be needed. However, if particulate emissions were cut to four metric tons per day or less, the source would pass the level-1 screening test, and further analysis would be unnecessary. 64 4 LEVEL-2 VISIBILITY SCREENING ANALYSIS A level-2 visibility screening analysis should be carried out when a level-1 screening analysis shows a potential for adverse or significant impairment. The level-2 analysis is based on more detailed information regarding the emissions source, regional meteorology, and other physical specifications of the site such as background visual range, ozone concen- tration, and topography. The primary objective of this level-2 analysis is to calculate the magnitude of visual impact that would be exceeded approximately one day per year. If the magnitude of this reasonable worst -case condition is less than some threshold value, one could be assured that an adverse or significant impact would not occur and further assessment would be unnecessary. 4.1 IDENTIFICATION OF WORST -CASE CONDITIONS The following factors should be considered when identifying the reasonable worst -case conditions for a level-2 visibility screening analysis: > Locations of emissions source and class I area(s) > Wind speed > Wind direction > Atmospheric stability and mixing depth > Time of day and season > Background ozone concentration > Background visual range > Persistence of meteorological conditions > Topographical effects on plume transport and diffusion. 65 Many of these factors have to be considered in any event when analyz- ing air quality impacts from a proposed emissions source in order to determine whether the source complies with ambient air quality standards and PSD increments. However, visibility impact assessments differ from air quality impact analyses in one important respect: air quality impact analyses are concerned with time -averaged, ground -level contaminant con- centrations, whereas visibility analyses are concerned with instantaneous NO2 and particle line -of -sight integrals, not necessarily at ground level. In the following paragraphs we discuss each of these factors and the manner in which overall worst -case conditions should be selected for level-2 visibility screening analyses. 4.1.1 Location of Emissions Source and Class I Area(s) The first step is to identify the location of the emissions source and the class I area(s) that may be affected. Some of this work will have been performed as part of the level-1 screening analysis that identified the minimum distance between the emissions source and the class I area. The Federal Land Manager(s) of the potentially affected class I area(s) should be contacted so that important integral vistas (i.e., with views from inside to outside of the class I area) can be selected for analysis. All class I areas that may be adversely affected, as indicated by the level-1 screening test, should be considered in the level-2 analysis. U.S. Geological Survey maps (scale 1:250,000) should be used to determine terrain elevations. These maps are recommended as a base upon which to draw the location of the emissions source, the locations at which meteorological data were collected, the boundaries of class I areas, and the particular class I area key observer points and integral vistas iden- tified for analysis. Also, it would be helpful for later analysis to draw the boundaries of each of the 16 cardinal (22.5° wide) sectors radiating from the site of the emissions source. Elevated terrain features that could potentially block the transport of a plume toward a class I area should be identified. (A significant terrain feature, such as a plateau, ridge, or mountain range, could pre- vent the direct transport of emissions toward a class I area.) A repre- sentative effective stack height of emissions should be calculated by add- ing to the physical stack height the plume rise for neutral conditions and the 50-percentile wind speed: H = hstack + eh 0 (P-8) The neutral plume rise is calculated using the following Briggs plume rise formula (Briggs, 1969, 1971, 1972): where oh = 1.6 F1/3 (3.5 x* 2/3 ) u_ 1 , (P-9) eh = plume rise, u = average wind speed in the layer through which the plume rises, F = buoyancy flux g J T 1 ---.� ambient (values of T in degrees Kelvin) stack g = gravitational acceleration = 9.8 m/s2, V =_ flue gas volumetric flow rate per stack, * 14 F5/8 ,if F < 55 m4s-3 34 F2/5 ,if F > 55 m4s-3 To this average effective stack height, add the elevation of the proposed site (above mean sea level) and 500 meters, which is the assumed addi- tional terrain ,height that is needed to block plume transport: 67 Zblock a Zsite + H + 500 m 0 (p-10) Shade the areas on the base map with elevations greater than this value. Trace plausible plume trajectories on this map that bypass the elevated terrain (shaded areas on the map). Examples of such plume trajectories are shown in figure 14. Note that stable plume transport directly toward observers A and B would be very unlikely. Stable flow would follow the curved trajectories shown in figure 14. Note that a stable plume would not likely be transported to observer C. althoUgh a stable plume near the emissions source might be visible to this observer. A straight-line tra- jectory to observer D in figure 14 is possible. It should be noted that a plume could be transported directly toward observers A, B, and C during neutral or unstable conditions; however, mechanically induced turbulence would increase the mixing of the plume, and visual impacts would be small. The distances along these plume trajectories will be used later as the downwind distance x to the class I area(s) for use in calculating plume transport times and diffusion. Elevation profiles of terrain at various azimuths from key observer points in class I areas that may be affected by the emissions source (see the example in figure 15) should be prepared. These plots should extend radially from the observer location to the most distant landscape feature visible from the given location, or to the average visual range for the area, whichever is less. From these plots the distance along the line of sight to various landscape features can be calculated. These plots and distances will be used in later analyses of plume perceptibility and land- scape -feature contrast reduction. 4.1.2 Meteorological Conditions The joint frequency of occurrence of meteorological conditions at the effective stack height of the emissions is needed to estimate the worst- OBSERVER OBSERVER OBSERVER ✓rat,, Figure 15. Examples of terrain elevation plots. 70 case meteorological conditions in the area associated with visual impacts that will be exceeded only about one day per year. The important meteorological parameters are > Wind speed Wind direction ? Atmospheric stability > Mixing depth. It is essential to consider the persistence as well as the frequency of occurrence of these conditions. For example, plume discoloration will generally be most intense during light -wind, stable conditions. However, the transport time to a class I area increases as the wind speed decreases. As the transport time approaches 24 hours, it is increasingly probable that the plume will be broken up by convective mixing and by changes in wind direction and speed; thus it will not be visible as a plume or a discolored layer. However, since increased haze often occurs because of secondary aerosols that take time to form in the atmosphere, visual range reduction may be more significant when transport times to a class I area are long. Largest increases in general haze (visual range reduction) resulting from an emissions source might occur if there is stagnation caused by synoptic meteorological conditions or topographical factors, or if there is trapping of emissions caused by upslope or down - slope flow reversals. Ideally, one would prefer to have a meteorological data base with detailed spatial and temporal coverage. However, this is rarely possible because of cost considerations. Several alternative approaches can be used to fill in missing data, but they all involve making assumptions. For example, if a complete meteorological data base is available only at the site of the proposed emissions source, one might assume that condi- tions at the site are representative of conditions at other locations in the region. However, in regions of complex terrain, like the example shown in figure 14, this assumption would not be appropriate. Often, data 71 collected at ground level are assumed to represent conditions at the effective stack height, which is a poor assumption when the plume is several hundred meters above ground or the site is located in complex ter- rain. Any assessment of air quality or visibility impacts is limited by the availability of meteorological data; more detailed assessments require more detailed and extensive data bases. Detailed visibility assessments, which are discussed in the next section of this document, require spatially and temporally resolved meteorological data. The level-1 screening analysis discussed in the previous chapter requires no meteoro- logical data; rather,.conservative assumptions are made regarding worst - case stability, wind speed, and wind direction. The level-2 screening analysis assumes that the analyst has at least one year of meteorological data from the site of the proposed emissions source, a nearby site within the region, or the class I area(s) potentially affected by emissions. The types of data bases for the level-2 analysis are listed as follows, in order of preference: > Concurrent upper air winds and stability. The best data base would provide hourly values of vertical temperature sgradients from which dispersion coefficients can be inferred and wind direction and speed vectorially averaged. If effective stack heights (physical stack height plus plume rise) are relatively low, these data can be collected from a meteorological tower. If the effec- tive stack heights are high, these data would have to be collected using rawinsondes, tethered balloons, or Doppler acoustic radar systems. A less desirable data base would consist of upper -air meteorological data gathered twice daily, such 4s those collected routinely by the National Weather Service. > Separate data sets. For some sites a good data base that consists of upper -air winds (e.g., from pibals) may be 72 available without concurrent lapse -rate (vertical tempera- ture gradient) data. In such situations, one can use _ lapse -rate data collected from another location in the region for the same or different periods for which wind data were collected. An assumption is made that the sta- bility at the other location is representative of the site and the class I area. If stability data are not available for the same period during which wind data were collected, the additional assumption must be made that wind frequen- cies and stability frequencies can be treated as inde- pendent probabilities, as discussed in chapter 2. > Surface data. Surface data (e.g., STAR data) may be appropriate if the effective stack height of the emissions is low or zero. However, surface data may be inappro- priate for evaluating the impacts of elevated releases. If no other data are available, one should use surface data with full recognition of the potential errors associated with their use; these errors may be extreme in complex terrain. If lapse -rate data are not available, one can estimate stability using the Turner method (1969). > No data. If meteorological data are not available, the assumptions regarding meteorology used in the level-1 analysis would be used to assess impact.* The Turner method (1969) should be used to determine stability categories that can then be used to assess plume dispersion using the oy and az curves of Pasquill-Gifford (Turner, 1969). It should be noted that dis- persion conditions at a given site may be considerably different from the idealized Pasquill-Gifford representations. Many different estimates of * For the analysis of plume discoloration, these conditions are F stability and a wind speed that would transport emissions to a class I area within 12 hours. For the analysis of potential haze due to sulfate aerosol, one would assume limited mixing conditions with a mixing depth of 1000 m and a wind speed of 2 m/$. 73 ey and az are available, such as the TVA, Brookhaven, and ASME curves. However, the Pasquill-Gifford curves are the most generally used and therefore have been adopted for use in this document. The Pasquill- Gifford az values may either overestimate or underestimate actual vertical diffusion in a given application. If diffusion data are available from tracer studies or from similar emissions sources in the region, such data could be used to assess more accurately potential plume visual impacts. 4.1.2.1 Worst -Case Conditions for Plume Discoloration* It should be emphasized that the vertical diffusion (oz) of a plume is the most important diffusion parameter for visibility impact assess- ments, because the optical thickness of a plume for horizontal lines of sight is inversely proportional to az, as shown in equations (19) and (20) . Specification of horizontal- diffusion (ay) is less important.t On the basis of the available -data base discussed previously, tables of joint frequency of occurrence of wind speed, wind direction, and stability class should be prepared that are similar to those shown in figure 16. These tables should be stratified by time of day. If meteoro- logical data are- available at hourly intervals, it is suggested that these tables be stratified as follows: 0001-0600, 0601-1200, 1201-1800, and 1801-2400. If data are available twice daily, morning and afternoon data should be tabulated separately. With this stratification, diurnal varia- tion in winds and stability are more easily discernible. * This step can be skipped if JC11 and IC21 from the level-1 analysis are each less than 0.1. t It should be noted that calculations of plume discoloration using the plume visibility model (PLUVUE) indicate that plume discoloration increases as plume a increases because of increased NO-to-NO2 conversion in well -mixed plumes. 74 MORNING HOURS ONLY (0001-0600); OTHER SETS OF TABLES FOR OTHER TIMES OF DAY Figure 16. Joint frequency distribution tables required to estimate worst -case meteorological conditions for plume discoloration 75 On the basis of the maps prepared previously, the analyst should select the wind direction sector that would transport emissions closest to a given class I area observer point so that the frequency of occurrence of impact can be assessed as discussed below. For example, in the schematic diagram shown in figure 17, west winds would transport emissions closest to observer A, whereas either west-southwest or west winds would transport emissions closest to observer B. Observer C would be affected by emis- sions transported by west-northwest and northwest winds, but primarily by west-northwest winds. For the situations influenced by complex terrain, such as the example shown in figure 14, the determination of this worst -case wind direction and its frequency of occurrence is much more difficult. The analyst should use professional judgment in this determination. The determination of the worst -case wind direction and its frequency of occurrence should be made on the basis of the following factors: > Location(s) for which meteorological data were collected relative to terrain features, emissions source, and potentially affected class I areas. > Likely plume trajectories for each wind direction (and possibly wind speed and stability) based on either data or professional judgment. For example, potential channeling, convergence, and divergence of flows should be assessed. The next step is to construct a table (see the example in table 1) that shows worst -case dispersion conditions ranked in order of decreasing severity and the frequency of occurrence of these conditions associated with the wind direction that could transport emissions toward the class I area. Dispersion conditions are ranked by evaluating the product azu, where oZ is the Pasquill-Gifford vertical diffusion coefficient for the given stability class and downwind distance x along the stable plume tra- jectory identified earlier, and u is the maximum wind speed for the given wind speed category in the joint frequency table. The dispersion condi- 76 ;EMISSIONS SOURCE Figure 17.- Schematic diagram showing emissions source, observer locations, and wind direction sectors. 77 TABLE 1. EXAMPLE TABLE SHOWING WORST -CASE METEOROLOGICAL CONDITIONS FOR PLUME DISCOLORATION CALCULATIONS Dispersion Condition Transport (Stability, Qz u Time wind speed) m2/s) (hrs) F, 1 90 56* E, 1 175 56* F, 2 180 19* F, 3 270 11 E, 2 350 19* F, 4 360 8 D, 1 430 56* F, 5 450 6 E, 3 525 11 Frequency of Occurrence of Given Dispersion Condition Associated with Worst -Case Frequency and Wind Directiont for Given Cumulative Tjme of D�y Frequency percent (percent) 0-6 6-12 12-18 18-24 f cf 0.2 0.1 0.0 0.2 0.0 0.0 0.3 0.2 0.1 0.2 0.0 0.0 0.2 0.1 0.0 0.2 0.0 0.0 0..2 0.2 0.0 0.2 0.2 0.2 0.4 0.3 0.0 0.2 0.0 0.2 0.3 0.2 0.0 0.2 0.3 0.5 0.0 0.2 0.5 0.1 0.0 0.5 0.1 0.1 0.0 0.1 0.1 0.6 0.5 0.3 0.1 0.3 0.5 1.1 * Transport times to class I areas during these conditions are longer than 12 hours, so they are not added to the cumulative frequency summation. t For a given class I area. U.j tions are then ranked in ascending order of the value ozu. This is illus- trated with an example in table 1. The downwind distance in this hypothe- tical case is assumed to be 100 km. Note that F,1 (stability class F associated with wind speed class 0-1 m/s) is the worst dispersion condi- tion, since it has the smallest value of czu (90 m2/s). The second worst diffusion condition in this example is E,1, followed by F929 F,3, and so on. The next column in table 1 shows the transport time along the minimum trajectory distance from the emissions source to the class I area, based on the midpoint value of wind speed for the given wind speed category. For example, for the wind speed category, 0-1 m/s, a wind speed of 0.5 m/s should be used to evaluate transport time; for 1-2 m/s, 1.5 m/s; and so on. The times necessary for a plume parcel to be transported 100 km are 56, 19, 11, 8, and 6 hours for wind speeds of 0.5, 1.59 2.59 3.5, and 4.5 m/s, respectively. For the level-2 screening analysis, we assume it is unlikely that steady-state plume conditions will persist for more than 12 hours. Thus, if a transit time of more than 12 hours is required to transport a plume parcel from the emissions source to a class I area for a given dispersion condition, we assume that plume material is more dispersed than a standard Gaussian plume model would predict. This enhanced dilution would result from daytime convective mixing and wind direction and speed changes. The objective of this tabulation of plume dispersion conditions is to identify the worst -case meteorological conditions. The joint frequency of occurrence of these worst -case meteorological conditions, associated with high background ozone concentrations and high background visual range, would be calculated by multiplying independent probabilities as discussed in chapter 2. This would define the frequency of occurrence of worst -case visual impact conditions. To obtain the worst -case meteorological condi- tions, ft is necessary to determine the dispersion condition (a given wind speed and stability class associated with the wind direction that would transport emissions toward the class -I area) that has a vzu product with a 79 cumulative probability of 1 percent. In other words, the dispersion con- dition is selected such that the sum of all frequencies of occurrence of conditions worse than this condition totals 1 percent (i.e., about four days per year). Dispersion conditions associated with transport times of more than 12 hours are not considered in this cumulative frequency for the reasons stated above. This process is illustrated by the example shown in table 1. It is seen that the first three dispersion conditions would cause maximum plume visual impacts, because the QZu products are lowest for these three condi- tions. However, the transport time from the emissions source to the class I area associated with each of these dispersion conditions is greater than 12 hours. With the fourth dispersion condition (F,3), emissions could be transported in less than 12 hours. The frequency of occurrence (f) of this condition is added to the cumulative frequency summation (cf). For this hypothetical example, the meteorological data are stratified into four time -of -day categories. The maximum of each of the four frequencies is used to assess the cumulative frequency. This is appropriate since we are concerned with the number of days during which, at any time, disper- sion conditions are worse than or equal to a given value. Note that the worst -case, stable, light -wind dispersion conditions occur more frequently in the nighttime hours.* In our example, the fol- lowing additional worst -case dispersion conditions add to the cumulative frequency: F.4; F,5; and E,3. Dispersion conditions with wind speeds less than 2 m/s (F,1; E,1; F,2; E,2; and D,1) were not considered to cause an impact because of the long transit times to the class I area in this example. Thus, their frequencies of occurrence were not added to the cumulative frequency summation. The result of this example analysis is * Nighttime visual impacts, such as obscuration of the view of the moon or the Milky Way, are not usually a concern. However, significant visual impacts could be caused in the morning after a period of nighttime transport. :k that dispersion condition E,3 is associated with a cumulative frequency of 1 percent, so we would use this dispersion condition to evaluate worst - case visual impacts for the level-2 screening analysis for this example case. It should also be noted that if the observer point in the class I area is on or near the boundary of one of the 16 cardinal wind direction sectors, it may be appropriate to interpolate the joint frequencies of wind speed, wind direction, and stability class from the two wind direc- tion sectors, on the basis of the azimuth orientation of the observer relative to the center of the wind direction sectors. 4.1.2.2 Worst -Case Conditions for General Haze* A similar procedure should be used to identify the potential worst - case limited mixing conditions for the region used in calculating worst - case haze increases caused by sulfate aerosol formed from S02 emissions. Most significant increases in general haze caused by emissions from a given source are likely to occur after a long period of transport during light -wind conditions when the vertical mixing is limited by a capping stable layer. In the level-1 analysis, we assumed that limited mixing conditions with a mixing depth of 1000 m and a wind speed of 2 m/s per- sisted for two days without precipitation (which would wash out par- ticulates, S02 and SO4-). In the level-2 analysis, assumptions appro- priate to the area being analyzed should be used. Two alternative approaches to this analysis can be considered. The first assumes concurrent mixing depth, wind speed and wind direction data for the site or region. The second assumes the absence of these data. The first approach is more time-consuming, but presumably more accurate, than the second. * This step can be skipped if IC31 from the level-1 analysis is less than 0.1. Let us consider the first approach. If one has vertical temperature gradient data for a region, one can calculate maximum daily mixing depths in a manner similar to that used by Holzworth (1972). These data should be sorted to identify periods without precipitation for at least two days. The remaining occurrences should be used to generate joint fre- quency tables similar to those shown in figure 18. Occurrences are sorted into different categories of maximum 48-hour mixing depth and 48-hour vector -average wind direction and wind speed. The vector -average wind direction and speed (i.e., the resultant wind) are defined by calculating a position vector as follows: t0 + 48 hr r = v (x,y,z,t) dt , t0 where r is the position vector and v (x,y,z,t) is the spatially and tem- porally dependent wind vector for the plume parcel emitted by the source. The vector -average wind direction is defined by the direction of the vector r and the vector -average wind speed is The next step parallels the procedures used to identify the worst - case meteorological conditions for plume discoloration. The analyst should construct a table of worst -case limited mixing conditions ranked in decreasing order of severity (increasing product of mixing depth Hm and wind speed u). Table 2(a) shows how such a table might be constructed. Different wind directions in which a class I area is located are iden- tified in this table from a map similar to the example in figure 19. This map shows 16 wind direction sectors and circles with radii corresponding to d values of 1, 2, 3, and 4 m/s (r = 1739 3469 518, and 691 km, respectively). For each limited mixing condition (u H m ) and wind direc- tion combination, the number of nonoverlapping 48-hour episode occurrences in a year is tabulated. If a class I area is located within the bounds 82 Figure 18. Joint frequency distribution tables required to estimate worst -case meteorological conditions for visibility impairment due to so emissions. 83 TABLE 2. EXAMPLE TABLE SHOWING WORST -CASE LIMITED MIXING CONDITIONS FOR HAZE CALCULATIONS (a) Based on Site/Regional Data Number of Occurrences of Indicated Limited Mixing Condi- Impact Frequency Limited Mixing tion in a Year Associated with and Cumulative Condition u Hm Wind Direction in Given Sector Frequency (u, FM)* (m2/s) SW W WNW NNW ENE f cf 1; 500 500 0 0 0 0 0 0 0 2; 500 19000 0 0 0 0 0 0 0 1; 1,000 19000. 0 0 0 0 0 0 0 3; 500 1,500 0 0 0 0 0 0 0 1; 1,500 1$00 0 0 0 0 0 0 -0 2; 19000 29000 0 0 0 0 0 0 0 4; 500 2,000 (1)§ 0 1 0 0 1 1 5; 500 29500 0 0 0 0 0 0 1 3; 19000 3,000 (2)§ 0 0 1 0 1 2 2; 1,500 3,000 1 1 0 0 0 2 4 * In units of m/s for u and m for Hm. t Wind direction sector is defined as the direction from which the wind blows, so areas A and B are affected by SW winds because they are located in the NE sector. § Parentheses indicate that, though a given combination of u, Hm, and wind direction occurred, no class I areas were located within the corresponding sector -distance. TABLE 2 (Concluded) (b) Based on Holzworth (1972) Data (example is based on Winslow, Arizona data) Number of Days per ited Mixing Episode -Days in Five -Year Year in a Class I Condition u Hm Period after a Minumum Number of Sectors Area Sector u ) m2/s of 48-hours Transport with Class I Areast f§ cf 2; 500 19000 2 4 0.10 0.10 2; 1,000 29000 22 4 1.10 1.20 4; 500 29000 33 3 1.24 2.44 2; 1,500 39000 2 4 0.10 2.54 6; 500 39000 1 2 0.03 2.57 2; 2,000 49000 0 4 0.00 2.57 4; 1,000 49000 80 3 3.00 2.57 ; 1,500 6,000 54 3 2.03 7.60 1,000 69000 21 2 0.53 8.13 2,000 81,000 11 3 0.41 8.54 19500 99000 21 2 0.53 9.07 29000 129000 30 2 1.13 10.20 units of m/s for u and m for Hm. ber of wind direction sectors with class nd speed class (0-2, 2-49 4-6, m/s). ese numbers are calculated as follows: I areas within radii corresponding to given (episodes/five-year period) (no. of sectors) (5 one-year periods/five-year period) (16 sectors) __ _ cnI I. Figure 19. Example map showing class I areas in region around emissions source and -wind direction/speed sectors. (Note: Class I area locations are shown at lettered points.) defined by the wind direction sector boundaries and the wind speed class radii, the occurrence is added to a cumulative frequency total. We proceed until we have identified the worst -case condition with a cumula- tive frequency of four occurrences in a year. In the example shown in table 2(a), this worst -case condition is a wind speed of 2 m/s and a mix- ing depth of 1500 m. The second approach should be used if site mixing depth data are not available or if analytic resources and time are limited. This approach uses information from Holzworth (1972), which shows, among other things, the number of episodes and episode -days without significant precipitation in a five-year period, with mixing depths and wind speeds less than given values persisting for at least two days. Using this second, simpler approach, we tabulate the number of epi- sodes in five years with given conditions as shown in table 2(b). Holzworth (1972) gives cumulative frequencies (number of episodes and episode -days) of u < u' and Hm < Hm'. For our purposes we need to convert these to frequencies in a given u and Hm category, as shown in table 2(b). The number of episode -days in a five-year period within a given limited mixing category is determined from Holzworth (1972) in the manner illustrated in table 3. First, the number of episodes (cfe) and the number of episode -days (cfd) in five years is tabulated for each mixing depth and wind speed category. The number of days in five years that were preceded by the given limited mixing condition persisting at least 48 hours is calculated from the difference, cfd - cfe. To convert these cumulative frequencies to frequencies within each mixing depth/wind speed category, one must subtract the frequencies of the appropriate categories as shown in table 3. We convert these frequencies to episode -days per year within a given wind direction sector and wind speed class radii in which class I areas are located as shown in the footnote in table 2(b). We determine an episode -day cumulative frequency equivalent to four days per year. For the example shown in table 2(b), this worst -case limited mixing condition is u = 4 m/s and Hm = 1000 m. If the cumulative fre- quency of occurrence of these extreme limited mixing conditions is less 87 TABLE 3. EXAMPLE TABLES SHOWING COMPUTATION OF DAYS IN A FIVE- YEAR PERIOD WITH THE GIVEN LIMITED MIXING CONDITION Number of Days in Five Years Upper Limits of Number of Occurrences Preceded by at Limited Mixing in a Five -Year Period Least 48 Hours of Category (from Holzworth, 1972) a Given Limited u Hm Episodes Episode -days Mixing Condition (m/s) (m) cfe cfd cf2+ = cfd - cfe 2 500 2 4 2 4 500 13 48 35 6 500 13 49 36 2 1000 13 37 24 4 1000 37 174 137 6 1000 42 197 155 2 1500 17 43 26 4 1500 52 245 193 6 1500 62 294 232 2 2000 17 43 26 4 2000 59 263 204 6 2000 75 348 273 Mind Speed (m/s) 0-2 2-4 4-6 Mixing Depth (ai) 0-500 500-1000 1000-1500 1500-20DO 2 24 26 26 2 22 2 0 (24-2) (26-24) (26-26) 1 4 7 10 35 237 193 204 33 (35-2) 80 (137-35-22) 54 (193-137-2) 22 (204-193-0) 2 5 11 36 155 232 273 1 (36-35) 17 (155-36-22-80) 21 (232-165-2-54) 30 (273-232-11-0) 3 1 6 19 112 Mote: Examples are based on data for Winslow. Arizona. from Nolzworth (1972). cfd-cfe f2+ n a OF CALCULATION than four days per year for the given region, we use the annual median mixing depths and wind speeds for the region (also given in Holzworth [1972]). Finally, regardless of which method is Used, the seasonal average afternoon wind speeds and mixing depths for the region should be tabulated on the basis of Holzworth (1972) for later use. 4.1.3 Background Ozone Concentration As noted in chapter 2, an important input parameter to the visibility model is the background ozone concentration, that is, the concentration of ozone outside the plume. Since we are concerned with background ozone concentrations at the effective stack height, which may be several hundred meters above ground, we must interpret ground -level ozone concentration data with care. In their analysis of long-term ozone concentration data at remote U.S. sites, Singh, Ludwig, and Johnson (1978) reported that there is a significant diurnal variation in ozone concentrations at the surface because of the surface depletion of ozone. They reported a significant reservoir of ozone in the free troposphere varying in concentration from about 30 ppb in the winter to about 60 ppb in the summer. The tropospheric ozone is rapidly mixed to the ground during the daytime; this causes surface con- centrations near the free tropospheric value. However, at night and in early morning, ozone is no longer mixed to the ground because of the development of a ground -based stable layer. During this period, ground - level ozone concentrations gradually decrease as a result of a surface depletion mechanism. In relatively remote, unpolluted regions, one would not expect a significant anthropogenic source of ozone. In figure 20, the vertical ozone structure and diurnal and seasonal variations in ozone con- centration are shown schematically. Since we are concerned with ozone concentrations at plume altitude in visibility calculations, it is appropriate to use the daily maximum value '- Free troposphere Ozone (Os) E lt Ito b s s � Z t _ so � c 0 Top of the afternoon p mooed layer ..... .............. Morn&np 07 Afternoon � Afternoon 03"AhCUt Oy with Pollution pollution 0e Diurnal profile I 0 to 40 e0 e0 too 120 0 s 10 is to is Ozone, ppD local time, It ito too eo 0 o so e M 10 O to 0 III (�) Direct 03 transport _ from uroon centers Local atone synthnis ?.\ Due to natural NOR Natural Ozone .,1,�,�• �' ., •:ti; ,rite_ I I I I I IV JwN man MAY JUL aePt a Month Source: Singh, Ludwig, and Johnson (1978). Figure 20. A schematic of the vertical 03 structure and its diurnal and seasonal variations at remote sites. N of the surface concentration to represent the daily average concentration at plume altitude, as shown in figure 20(a). We select a median background ozone concentration for the assessment of worst -case visual impacts, so, by definition, the frequency of occur- rence of ozone concentrations higher than that assumed is 50 percent. This is done so that when the cumulative frequencies of occurrence of meteorological conditions worse than the assumed worst -case meteorological conditions are multiplied by the corresponding frequencies of high back- ground ozone concentration and visual range, the resulting cumulative fre- quency is the equivalent of one day per year. Thus, we have (cumulative frequency of assumed worst -case meteorological conditions) x (cumulative frequency of assumed background ozone concentration) x (cumulative frequency of assumed background visual range) = 0.01 x 0.50 x 0.50 x 365 days/year Lz 1 day/year. 4.1.4 Background Visual Range As noted previously, we want to select the median background visual range to analyze worst -case visual impact conditions. The impact - magnitude calculations described in the next section are based on the assumption that visual range is calculated at a wavelength a of 0.55 vm: 3.912 rv0 = b ext a = 0.55 um Since there can be a significant wavelength dependence of bext, it is important that the median background visual range for the site and region is based on spectral measurements at 0.55 on. Such measurements can be made with telephotometers or nephelometers equipped with narrow band-pass filters. If such data are not available, use the estimates of median regional visual range shown in figure 13. 91 4.2 HAND CALCULATION OF WORST -CASE VISUAL IMPACTS From the procedures discussed previously, the analyst will have iden- tified the following conditions for calculation of worst -case impacts: > Worst -case (1-percentile) plume dispersion condition. - Worst -case wind direction (one of sixteen 22.50 sectors). - Wind speed. - Pasquill-Gifford stability class. > Worst -case (1-percentile) and seasonal average limited mixing condition. - Wind speed. - Mixing depth. > Median (50-percentile) background ozone concentration. > Median (50-percentile) background visual range. > Distances to terrain objects for various line -of -sight azimuths. > Downwind distance x along plume trajectory. In this section we discuss the calculation of visual impact parame- ters on the basis of those worst -case conditions appropriate for a level-2 visibility screening analysis. We suggest four different alternatives for calculating magnitudes of worst -case visual impacts: > Hand calculations of plume contrast and sky/terrain con- trast reduction using equations (10) and (14) from chapter 2, and procedures presented in this section. > Reference tables of plume discoloration parameters corres- ponding to various NO2 line -of -sight integrals. > Reference figures of visual range reduction caused by emissions sources of different sizes for various meteoro- logical conditions. > Computer model calculations using PLUVUE or some other equivalent visibility model. 92 The analyst can choose which of these methods to use for a level-2 screening analysis, depending on personal preference. However, more accurate estimates (with less conservatism) are possible with the use of computer model calculations. Assessments using different alternative methods can be cross-checked. We can compute the magnitude of visibility impact corresponding to the worst -case conditions identified earlier in this section by a series of formulas presented here. Some of these calculations are needed to use the reference tables and to set up input for the computer model. 4.2.1 Determining the Geometry of Plume, Observer, Viewing Background, and Sun In the previous section we discussed the procedure for identifying the worst -case meteorological conditions used in the calculation of visi- bility impacts. This condition was selected so that on only one day per year (on the average) would conditions be worse than those selected for analysis. As the basis for the selection of this condition, we considered the frequency of occurrence of wind directions that would carry emissions within the 22.5' sector centered on the observer, as shown schematically in figure 21. Thus, we have identified the cumulative frequency (i.e., the fre- quency of occurrence of conditions worse than the given value) of wind directions within the worst -case wind direction sector associated with (1) wind speeds less than, (2) stabilities greater than, (3) background ozone concentrations greater than, and (4) background visual ranges greater than, the given values selected for the worst -case impact evaluation. Because we wish to compute the magnitude of plume visual impact, it is appropriate to consider the plume orientation resulting in the smallest impact associated with the worst -case wind direction sector. Thus, we consider a plume centerline at the edge of the 22.5° sector centered on 93 Figure 21. Locus of plume centerlines within worst -case wind direction sector. 94 the observer, as shown in figure 22. Thus, the minimum distance between the observer and the plume centerline is 0 rp-min ' x tan 22.5 = 0.199 x , 2 where x is the downwind distance along the plume centerline from the emis- sions source to the parcel that is observed, as shown in figure 22. For the worst -case plume discoloration condition, the plume is assumed to have a Gaussian distribution in the vertical direction, with vertical dimensions as a function of the Z corresponding to the given worst -case stability class and downwind distance x. For level-2 screening performed on the basis of hand calculations, we further assume that the plume material is uniformly mixed in the horizontal direction within the 22.5' sector. Thus the plume width at a given downwind distance is twice rp-min, or 0.398 x. For the worst -case general haze conditions one must remember the assumption that plume material has been transported for two days. There- fore, for the evaluation of increases in haze resulting from S02 and par- ticle emissions during worst -case 48-hour episodes of limited mixing, we assume that the plume width is 100 km. Several studies suggest that plume spread is a function of travel time and that this 100 km width is a reasonable representation for a 48-hour travel time (see, for example, model calculations of Liu and Ourran, 1977, and field data of Randerson, 1972). For the level-2 analysis (based on hand calculations), we also assume that the plume width is constant within the field of view, as shown in figure 23. This plume width equals 2rp-min (0.398 x, or 100 km). Both the plume optical thickness, 'plume, and the distance to the plume center- line are inversely proportional to the size of the angle a shown in figure 95 FA LL111..1&wllJ JVVIAVV Figure 22. Observer -plume orientation for level-2 visibility screening analysis. 96 23. Thus, _ pl ume (a = 900 ) Tplume(a) sin a r rin p(a) sinma 9 Also, the plume optical thickness between the observer and a given viewed object is a function of the object -observer distance ro: p 1 ume (a) ' Tplume(r0, a) - r Tplume(a) rp 0 a if ro > 2rp (a) , if ro < 2rp( a) The distances ro and the azimuths for various terrain viewing objects identified using the procedure discussed previously in this section (see figure 15) should be tabulated. The corresponding values of a and scat- tering angle a should be identified in this table also. The scattering angle 9 for horizontal lines of sight can be determined as follows (Duffie and Beckman, 1974): where cos e = cos d sin A sin H + sin d cos � cos A - cos d sin � cos A cos H , (p-11) A = azimuth of the line of sight from observer to viewed object (e.g., A = 0' for the line of sight directly to the north), d = declination, 97 W OBJECT * iB w• ..urn. uwT �e.t w• WL/.JLI%W 1-9% Figure 23. Plan view of assumed plume -observer geometry for level-2 visibility screening calculations. e 23.45 sin 360 284 365 n degrees , n - number of the day of the year (e.g., 1 January is n latitude of the observer, H = hour angle, solar noon being zero, each hour equiva- lent to a 15' displacement, mornings positive and afternoons negative. Note that stable plumes are usually viewed in the morning at, or shortly after, sunrise. The scattering angle 0 at sunrise at a spring or autumnal equinox is determined for d = 0' and H = 90' as follows: cos 0 = sin A Thus, for these dates and this time 0= IA - 90°1 , 4500 - A , if 900 < A < 270° if A > 2700 The value of the scattering angle and the appropriate line -of -sight azimuth A should also be evaluated for the following values of a: 30', 4509 6009 90'9 120'9 135', and 150'. Note that both A and a are azimuthal angles descriptive of the line of sight. A is referenced to north and a is referenced to the plume centerline. 4.2.2 Calculating Plume Optical Depth We start with known emission rates of primary particulate matter, NOx, and S02 from the source. To convert these quantities to plume opti- cal depth (t), we must know > Size distribution and density of emitted particles. > Size distribution and density of secondary sulfate aero- Sol. > Fraction of NOx and S02 emissions converted to NO2 or sul- fate (SO4=) aerosol at a given downwind distance (or transport time). > Vertical distribution of plume material. > Wind speed. 4.2.2.1 Effects of Primary Particulate Emissions on Optical Depth If the size and density of primary particle emissions are known, we can compute the plume flux of the scattering coefficient from the follow- ing formula: where 1160 Qpart(bscat/V) Qscat-part r (p-12) P Qscat-part = plume flux of scattering coefficient at A = 0.55 un (m2S-1), Qpart = Primary particle mass emissions rate (metric tons/day), (bscat/V) = scattering coefficient (at 7► = 0.55 um) per unit volume concentration of aerosol [10-4m-1/(un3/cm3)] from figure 24, P - density of primary particles (g/cm3). Note that the conversion factor in this equation derives from the use of the units given above: - r (metric tons/day) (106g/metric ton) [(10 m )/(-on3/cm )] •.(24 hr/day) (3600 s/hr) (g/cm3) (100 cm/m)3 (10-4cm/ un)3 = 1.16 x 103 m2s-1 100 0.1 0.0 0.001 L 0.1 MW j GEOMETRIC o = 2 I STANDARD DEVIATION +----ACCUMULATION MODE ! COARSE ---* MODE f 1 1.0 10.0 Mass Median Diameter (DG) Source; Latimer et al. (1978). Figure 24. Scattering -to -volume ratios for various size distributions. 101 If one does not know the primary particle size distribution and den- sity, one can assume the values used for the level-1 analysis --a mass median diameter DG of 2 vm, a geometric standard deviation ag of 2, and a density of 2.5 g/cm3 (Schulz, Engdahl, and Frankenberg, 1975). For this distribution we have (bscat/V) = 0.025, and therefore Qscat-part 11.6 Qpart (P-13) Another alternative is to use the known stack opacity to calculate the plume scattering coefficient.* Sometimes the stack opacity is known with more precision than is the mass emission rate for primary par- ticles. If both the stack opacity and the particle mass emission rate are known, we can compute the appropriate size distribution that will provide a match. The stack opacity is defined as follows: Opacity = 1 - e `stack Is (p-14) where T QscatD-part , D =_ inside stack diameter, and v = flue gas stack stack exit velocity. lows: We can solve for the scattering coefficient flux per stack as fol- Qscat-part - -D v Rn(1 - Opacity) 0 (p-15) For many facilities, emissions regulations limit stack opacity to 20 percent. For such facilities * A caution is in order here. If wet scrubbers are used or if hygroscopic material or condensable gases are emitted fhom the source, it may not be appropriate to calculate the plume flux of scattering coefficient from stack opacity because particles may quickly grow and form as flue gas temperature drops. 102 Qscat-part = -D v Rn(1 - 0.20) = 0.22 D v (p-16) The total plume scattering coefficient flux is the sum of the contri- butions from all stacks in the facility. Note, however, that as a result of differences in stack height or plume rise for different stack emis- sions, stable plumes from different elevations in the facility may be at different elevations, without overlap. In such cases, for the calcula- tion of stable conditions, one would use the maximum single -stack scatter- ing coefficient flux only, not the sum over all stacks. This would be true for NO2 fluxes also. For the calculations of increases in haze caused by S02 and particle emissions during limited mixing conditions, however, one should use the emissions over all stacks because all emis- sions are assumed to be uniformly mixed within the mixed layer. If one has both the mass emissions rate and the stack opacity, one can solve these equations for (bscat/V), assuming a particle density of 2.5 or some other appropriate value, and one can use figure 24 to deter- mine the corresponding size distribution. The scattering coefficient flux is calculated on the basis of a wave- length A of 0.55 Un. The scattering coefficient (resulting from particles only) at any wavelength can be calculated from the following equation: bscat(X) = bscat (X = 0.55) -n , (p-17) where n is given in table 4 as a function of mass median diameter for a size distribution whose geometric standard deviation is vg = 2. Note from table 4 that for particle size distributions with mass median diameters larger than about 1.5 um, the scattering coefficient is independent of wavelength over the visible spectrum. However, for a typi- cal submicron aerosol with a mass median diameter of 0.3 um, the scatter- ing coefficient at A = 0.4 um (the blue end of the spectrum) is 2.5 times larger than that ,at a = 0.7 um (the red end). 103 TABLE 4. WAVELENGTH DEPENDENCE OF SCATTERING COEFFICIENT AS A FUNCTION OF PARTICLE SIZE DISTRIBUTION Mass Median Diameter DG* t ( un) n 0.1 2.8 0.2 2.1 0.3 1.6 0.4 1.2 0.5 1.0 0.6 0.7 0.8 0.5 1.0 0.2 1.5 0 * Geometric standard deviation ag = 2. -n t n is defined as follows: bscat( ) b at( ) �1 sc a2 '2 (appropriate for 0.4 < A < 0.7 un) . 104 The corresponding plume fluxes of scattering coefficients resulting from sulfate aerosol, and absorption coefficients resulting from NO2, are more difficult to calculate since one has to consider the rate of forma- tion of sulfate or NO2 from S02 and NOx emissions.* 4.2.2.2 Effects of Nitrogen Dioxide on Optical Depth We first consider the NO2 absorption coefficient plume flux. We assume that, for the two-day limited mixing stagnation case, all NO2 is scavenged by reactions with the hydroxyl radical (OH-), forming nitric acid vapor (HNO3), or from surface deposition. However, for the stable plume transport case used to calculate worst -case plume discoloration, nitric oxide (NO) emissions will react with background ozone and oxygen to form NO2. The fraction of NOx emissions that is converted to NO2 can be calcu- lated with formulations used in the visibility computer model (see Latimer et al., 1978). This fraction is dependent on the spatial and temporal variation in ultraviolet radiation, background ozone, and plume S02 and NOx concentrations. However, for stable, nighttime transport cases, a reasonable, somewhat conservative estimate of this fraction can be made as follows: first, we assume that NOx emissions are uniformly distributed horizontally over a 22.5° sector. Thus, NOx concentrations can be calcu- lated as follows: QNO x [NO ] x (2v)1/2 Zu [2 tan 22'S x, * For those who will use the computer model or the reference figures based on the computer model runs, these calculations of NO2 and SO4- formation can be omitted. 105 This can be simplified, using appropriate conversion factors for the units indicated, as follows: where 6.17 QNO [NOXI = a ux x (P-18) z [NOx] = plume centerline NOx concentration (ppm), QNOX = mass emissions rate of NOx, expressed as NO2 (metric tons per day), oz = Pasquill-Gifford dispersion coefficient at down- wind distance x, u = wind speed (m/s), x = downwind distance. For example, this formula yields an NOX concentration of 0.034 ppm 100 km downwind from a 100 metric ton/day source during f stability and 2 m/s wind conditions. Using a simplified formulation from Latimer et al. (1978). appropriate for stable nighttime transport and early morning situations, we can calculate NO2 concentrations in the plume as follows: where h , CNo2J = [NOxJ if [NO x] ;0 h if [NO x] < h [NO2] = plume centerline NO2 concentration (ppm), h = 0.1 [NOx] + [03]9 [NOx] = as defined above, [03] = background ozone concentration (ppm). (P-19) For the example shown above, if the background ozone concentration is a typical value of 0.04 ppm, we calculate an NO2 concentration of 0.034 ppm, indicating that complete conversion of NO to NO2 occurred. 106 For viewing situations in which the sun is high above the horizon, this formula overestimates NO2 concentrations. For such applications, either the visibility model or the following formulation should be used to obtain more accurate determinations (Latimer et al., 1978): [NO.5[NO]+h+-1/2 2]=0x J ([NOx] + h + j)2 - 4[NOx]h (p-20) where j = 2.3 x 10-2 exp (-0.38/cos Zs); Zs = solar zenith angle, the angle between direct solar rays and the normal to the earth's surface (e.g., Zs = 900 for sunrise or sunset; Zs = 0° for sun directly overhead); [NO2]9 [03], [NOx], h are defined as above. The optical depth resulting from NO2 is simply TNO 2 = 0.398 [NO 2](x)(babs/ppm) 9 (p-21) where x = downwind distance (km), and (babs/ppm) =_ light absorption per ppm NO2 (km-1ppm-1). The value of (babs/ppm) for NO2 as a function of wavelength is plot- ted in figure 25. Note the extreme variation with wavelength (the plot is on logarithmic paper). Light absorption by NO2 is more than two orders of magnitude larger at the blue end of the visible spectrum (a = 0.4 un) than at the red end (a = 0.7 um). The values at the three wavelengths that we will use later to calculate contrasts are as follows: 107 0.5 0.4 0.3 E Q a 0.2 N C) E a 0.1 V) .0 fp 0.05 0.04 0.03 M i1 0.01 L 0.4 w 0.5 0.6 0.7 Wavelength a (um) Note: Based on data from Nixon (1940). Figure 25. Wavelength dependence of light absorption of nitrogen dioxide (NO2)• babs/ppm (km-lppm-1) 0.40 1.71 0.55 0.31 0.70 0.017 4.2.2.3 Effects of Secondary Sulfate Aerosol on Optical Depth The scattering coefficient for sulfate aerosol is determined from an empirical formula (Latimer et al., 1978): b / (Ijg/m3 ) 2.5 x 10-6 m-1( ug/m3 } scat f a = 0.55 um RH 0 ' where RH is the average relative humidity (in percent) for the area. If this relative humidity is not known for the given area, assume 40 percent and 70 percent for the western and eastern United States, respectively. This sulfate aerosol is assumed to have a size distribution with a mass median diameter of 0.3 um and a geometric standard deviation of 2. The sulfate aerosol mass flux in the plume at a given distance down- wind is calculated from the emission rate of S02 as follows: where f MW kf QSO QSO4 = (k + k2 1 - exp[-(kf + kd) t] f d) QSO4 =_ plume mass flux of sulfate aerosol, fMW ratio of molecular weights of SO4= and S02 = 96/64 = 1.5, M kf'- 24-hour average pseudo -first -order rate constant for S02 conversion to SO4= in the atmosphere, kd - 24-hour average pseudo -first -order rate constant for -surface deposition = vd/Hm, t - plume parcel transport time (for the level-2 analysis we assume t = 48 hours), vd - 24-hour average'S02 deposition velocity (we suggest using vd = 0.5 cm/s), Hm = mixing depth. On the basis of calculations of homogeneous oxidation rates by Atlshuller (1979), we suggest that the following values be used for the 24-hour average S02-t0-SO4= pseudo -first -order rate constant kf. kf Season %/hr) Winter 0.1 Spring, autumn 0.2 Summer 0.4 The analyst should use the appropriate values of the mixing depth, Hm, for the limited mixing worst -case and for the seasonal -average condi- tions that were identified -by the procedure described previously. = mass flux and scattering coef- We may combine equations for SO4ficient per mass concentration to obtain a formula for the SO4= scattering coefficient plume flux. This formula, with appropriate conversion factors for the units shown, is as follows: 43.4 kf QSO 2 r Rscat-SO4 k' (1 - RH/100) L1 - exp(-0.48 k')1 , (p-22) 110 where k' - kf + 1800/Hm, and kf is taken from the tabulation shown above, QS02 is in metric tons per day, RH is in percent, and Hm is in meters. The plume scattering coefficient flux values for primary particle emissions and for sulfate aerosol formed from S02 emissions can be conver- ted to plume optical thickness through division by the appropriate factor. Qscat- art (p-23) part - (2n) 2Q u z for Gaussian vertical profiles (e.g., the worst -case stable plume condi- tion), and Rscat-part + Qscat-SO 4 (p-24) aerosol uHm for vertically uniformly mixed plumes in the mixed layer 0 < Z < Hm (e.g_., the worst -case and seasonal -average limited mixing conditions). From the equations presented thus far, the analyst will be able to calculate the following optical thickness (T) values for any wavelength a: > TN02 and Tpart for the worst -case plume dispersion condi- tions ( assume no sulfate formation for these worst -case, light -wind, stable conditions). > Taerosol for worst -case limited mixing conditions and each of the seasonal -average limited mixing conditions. 4.2.3 Calculating Phase Functions The phase function, defined in equation (1) of chapter 2, describes the fraction of total light scattered by -a given plume or background 111 atmosphere parcel in the direction defined by the scattering angle 0. A scattering angle 0 of 00 means no change in radiation direction, while 180° means that radiation is scattered backward. Much more light is scat- tered in the forward direction (e < 90') than in the backward direction (0 > 900). We need to calculate phase functions to determine the amount of light that is scattered into an observer's line of sight. Phase functions p( a,e) for the plume and the background atmosphere are determined from the tables in appendix B. These tables show phase functions as a function of scattering angle [i.e., the angle between the direct solar radiation and the line of sight as shown in figure 2(a), chapter 2] for various particle size distributions and wavelengths a (0.4, 0.55, and 0.7 urn). Figure 26 summarizes the phase functions at a = 0.55 um. Note that p(e) is largest for small scattering angles (i.e., more light is scattered in the forward direction). To calculate average phase functions -for the background atmosphere, we must calculate the fraction of the total extinction coefficient result- ing from: > Light absorption by aerosols. > Rayleigh light scatter due to air. > Light scatter caused by submicron (accumulation mode) aerosol. > Light scatter caused by coarse aerosol. First, we must calculate the background extinction coefficient from the median visual range for the area: bext(� ' 0.55 um) 3.912 (p-25) v0 112 E Ln O n aJ b c 0 -f- 4J c U_ n� ro r o. 5 101 5 100 6j 5 10-2 L 0- DG 5.0 vm -------- 2.0 Um I ..._ _.. 1.0 um 0.5 Um 1 _....., 0.2 j,m -----O.l um �, "••• AIR ••`••••(RAYLEIGN SCATTER) NOTE. PHASE FUNCTIONS AT a = 0.55 um ARE SHOWN FOR PARTICLE SIZE DIS- TRIBUTIONS WITH INDICATED MASS MEDIAN DIAMETER (DG) AND GEO- METRIC STANDARD DEVIATION (vg = 2.0) 20 40 60 80 100 120 140 160 180 Scattering Angle a (degrees) Figure 26. Phase functions for various particle size distributions. 113 We assume that 3 percent of the background extinction coefficient is caused by light absorption resulting from aerosols such as soot.* Thus, bscat ( I = 0.55 on) = 0.95 bext (p-26) The scattering coefficient caused by particles is determined by sub- tracting the Rayleigh scattering coefficient: bsp( a = 0.55 um) = bscat( X = 0.55) - bR( a = 0.55) , (p-27) where bR(A = 0.55 on) = (11.62 x 10-6m-1) exp - Z+5 , and Z = eleva- tion of site (m MSL). Based on data of Whitby and Sverdrup (1978) and calculations of Latimer et al. (1978). the fraction of bsp caused by coarse particles is assumed to be 0.33.t Thus, we have bsp-submicron = 0.67 bsp (p-28) bsp-coarse = 0.33 bsp0 (p-29) The phase function for each of the scattering components can now be determined. Phase functions for the submicron and coarse background aero- * Charlson.and Waggoner, personal communication. t For marine background atmospheres (coastal locations unaffected by urban plumes), assume this fraction is 95 percent. For urban areas, assume this fraction is 10 percent. 114 Sol modes can be determined from appendix B. We assume that the back- ground submicron aerosol has a mass median diameter of 0.3 im and the background coarse aerosol has a mass median diameter of 6 w. Both of these aerosol modes are assumed to have a geometric standard deviation of 2.0. These size distributions are typical of those measured by Whitby and Sverdrup (1978) in a variety of environments, including clean and average rural and urban atmospheres. Phase.functions for these two size distribu- tions are given in appendix B. The Rayleigh scattering phase function (for air) is a function of the scattering angle e, but it is independent of wavelength A and can be approximated quite well by the following relationship: p(e) = 0.75 [1 + (cos e)21 (p-30) At this point the analyst should fill in a table similar to table 5 for the scattering angles (0) shown or for those identified for specific lines of sight, as portrayed schematically in figure 23. The scattering coefficients at different wavelengths can be determined from the relation- ship: bsp( a) = bsp( a = 0.55 VO ( X 0.55 un n 9 (P-31) where values of n are given in table 4 for various particle size distribu- tions and n = 4.1 for Rayleigh scatter. The average background atmosphere phase functions are calculated for each wavelength a and scattering angle a as follows: Ebsp( a) P(as e) P (A' d) l background bsp( a) (p-32) 115 TABLE 5. EXAMPLE TABLE SHOWING BACKGROUND ATMOSPHERE PHASE FUNCTIONS AND SCATTERING COEFFICIENTS Background Atmosphere Scattering Component a(up) bso(m'1) Rayleigh Scattering 0.40 Due to air molecules -..55 at site elevation 0.70 Mie Scattering' Submicron aerosol 0.40 DG = 0.3 on 0.55 vg = 2.0 0.70 Mie Scattering Coarse aerosol 0.40 DG=6un 0.55 ag = 2.0 0.70 Total (average) 0.40 0.55 0.70 Phase Function p( A,e) for Indicated e 22° 45° 900 1350 180' 116 where the summation is over Rayleigh, submicron, and coarse mode scatter- ing categories. The phase functions for the plume can be obtained from the tables in appendix B corresponding to the size distribution of the primary particle emissions. If this size distribution is not known, assume it has a 2.0 on mass median diameter (Schulz, Engdahl, and Frankenberg, 1975). f 4.2.4 Calculating Plume Contrast and Contrast Reduction With the procedure discussed thus far, the analyst can calculate the magnitude of plume visual impact using equations (10) and (14) from chapter 2. These equations are repeated here for convenience. Plume Contrast (p`�)plume Cplume = exp(- plume) exp(-bextrp) (p))background (p-33) Reduction in Sky/Terrain Contrast Caused by Plume AC = -00 exp(-bextro) 1 - m + )exp(-fobj'plume)plu a(p-34) where pplume' pbackground - average phase functions for plume and back- 117 ground atmosphere, respectively. p is a func- tion of a and o, * TN02 + Tpart + TSO4 T 1 ume sin a T is a function of p a an a, 0 plume 1 T 2, w i s a f unct i on of a, _ plume `$ ackground = 0.95 "(by assumption that 5 percent of total estimation is due to light absorption by aero- sol and that there is no background NO2, bext = background extinction coefficient bR( X) + bsp-submicronN + bsp-coarse( X) + bap( a)' (bext is a function of a), rp = plume -observer distance 0.199x for stable plume sin a 50 km ' for 2-day-old plume during sin a limited mixing conditions ro - object -observer distance, CO _ intrinsic sky/terrain contrast of viewed object (-0.7 to -0.9 for most terrain), fobj - fraction of total plume optical thickness between observer and viewed object. The analyst should calculate values of contrast for the following permutations: * It should be noted again that, for the stable plume case, there is no sulfate (SO4=), and for the two-day old plume during limited mixing conditions, there is no NO2. 118 > Meteorological conditions: the identified worst -case stable and limited mixing conditions and the seasonal - average limited mixing conditions. > Class I areas: all potentially affected class I areas as identified by level-1 analysis. > Line -of -sight azimuths: for all terrain features identi- fied for each class I area observer at various ro and a and also at standard values of a. > Wavelength: Certainly at a = 0.55 Un. Calculations at a = 0.40 and 0.70 un are recommended, especially for plume contrast (Cplume) calculations. If the absolute value of any plume contrast or contrast reduction value (at any wavelength) is greater than 0.10, one cannot rule out the possibility of adverse or significant visibility impairment. In such a case, one may choose (1) to modify source emissions or siting, or (2) to submit the results of the level-2 analysis or a more detailed (level-3) analysis to the appropriate government official for review and case - specific determination of the significance or adversity of the visual impact in the potentially affected class I area(s). 4.3 USE OF REFERENCE TABLES FOR NO2 IMPACTS As an adjunct to the hand calculations or as a replacement for some of the Cplume calculations, one may wish to use the reference tables in appendix C. These tables are appropriate only for emissions sources such as power plants, boilers, and other combustion sources that emit NOx, from which the principal plume colorant is NO2. One should not use these tables for a source with NOx mass emissions rates less than 5 times the particulate emissions rate. These tables provide values of the following parameters that describe the contrast of a plume against the horizon sky: > Blue -red ratio R: 1 + Cp 1 ume (a = 0.4 tin) R - 1+ Cplume(a= 0.7 tm) 119 > Plume contrast Cplume (X ' 0.55 un) > Plume perceptibility parameter eE(L*a*b*). To use these tables, calculate tpar0 for the worst -case stable plume condition only) on the basis of the procedures given earlier in this chapter, using the given particle mass emissions rate and size distribu- tion, az, u, and a. Compute the approximate visual range: ry = rv0 (1 - part/3.912) (p-35) Calculate the line -of -sight integral of plume NO2, in units of ug/m2, from the following formula: where [N0 ] dr = (7.49 - 105)(x)[N021 (p-36) plume 2 sin a x =_ downwind distance in km, [NO2] = NO2 concentration as calculated using procedures in the previous section, a = angle between the plume centerline and the line of sight. The analyst should use the appropriate table in appendix C for the given (reduced) visual range, NO2 line -of -sight integral, and plume - observer distance rp and determine the visual impact parameters from this table. _If the blue -red ratio is less than 0.90, if plume contrast is less than -0.10, or if AE(L*a*b*) is greater than 4.0, the probability of adverse or significant plume discoloration cannot be ruled out. 120 4.4 USE OF REFERENCE FIGURES FOR POWER PLANTS If the emissions source is a power plant, one of the figures in appendix D may apply to the case being evaluated. Note that the percen- tage visual range reduction is for a line of sight perpendicular to the plume centerline. The reduction in sky/terrain contrast at a = 0.55 un can be calculated from this percentage visual range reduction as follows: where AC = -CO exp (-3.912 ro/rv0 1 - exp - s 3.912 f obj sin a ' (p-37 ) fobj = fraction of plume between observer and object, AV = percentage reduction in visual range or line of sight perpen- dicular to plume centerline 100%, rv0 CO, ro, rv0, and a are as defined previously. 4.5 USE OF THE COMPUTER MODEL Probably the easiest and most accurate method for determining levels of impact is to use the plume visibility computer model (PLUVUE) initialized to the given worst -case conditions and geometry identified using the procedures presented in sections 4.1 and 4.2. The reader should refer to 'the separate document entitled, "User's Manual for the Plume Visibility Model (PLUVUE)", EPA-450/4-80-032, before using this model. 4.6 EXAMPLE CALCULATIONS The reader may refer to appendix E for two sets of example calcula- tions using the level-1 and level-2 analysis procedures. These examples 121 are hypothetical power and cement plants. 4.7 SUMMARY OF LEVEL-1 AND LEVEL-2 PROCEDURES Figures 27 and 28 (a through f) present a series of schematic, logic, flow diagrams that summarize the major steps of the level-1 and level-2 screening procedures. Once the reader has become familiar with the actual steps necessary to carry out analyses through level-2, these flowcharts can be used as a checklist. Several conventions in the flowcharts should facilitate their use. The specific section numbers in the workbook describing the individual steps are identified within each flowchart. The reader may, therefore, use the flowcharts to identify the location of various equations and pro- cedures presented in the text. A list of the variables for which numerical values have been determined in that step is presented at the end of each flowchart. This list can be used to locate the calculations lead- ing to each variable. In general, aside from the oval start -and -stop blocks in the flowcharts, three different shapes of blocks are used. Rectangular blocks indicate a straightforward procedure or calculation; diamond -shaped blocks indicate decision points with regard to whether further analysis is needed; and computer -card -shaped blocks (with clipped corners) indicate a data collection or interpretation, task. The presentation of a hand calculation procedure (section 4.2) is not intended to imply that some level of automation is not appropriate. Those users with access to a computer or programmable calculator can benefit from setting up segmented programs for the steps presented in the flow- charts, since the complexity of the calculations contributes to the like- lihood of undetected computational errors in results. These flowcharts can be used as the preliminary basis for developing the necessary computer language codes or calculator step sequences, and the accuracy of the results from such programs can be tested using the numerical values con- tained in the examples in the text and in -appendix E. 122 START DETERMINE DISTANCE x FROM EMISSIONS SOURCE TO CLASS I AREA LOOK UP VERTICAL DIF- FUSION COEFFICIENT QZ CALCULATE DISPER- SION PARAMETER p DETERMINE PARTICULATE, NOx, AND S02 EMISSION RATES Q 0 CALCULATE ESTIMATES OF OPTICAL THICKNESS t CALCULATE CONTRAST PARAMETERS C DETER- MINE WHETHER C. VALUES INDICATE THE NEED FOR LEVEL-2 ANALYSIS ALL 1C.1 < 0.1 STOP C.I Z 0.1 PERFORM LEVEL-2 ANALYSIS Figure 27. Logic flow diagram for level-1 analysis (see section 3.2) 123 START DETERMINE GEOGRAPHY IN THE VICINITY OF THE SOURCE AND CLASS I AREAS. IDENTIFY KEY VISTAS. DETERMINE STACK PARAMETERS RELATED TO PLUME BUOYANCY AND VELOCITY EFFECTS CALCULATE PLUME RISE AND LOCATE POSSIBLE TRAJECTORIES FROM SOURCE TO VISTAS DETERMINE TRANSPORT DISTANCES, ELE- VATIONS ALONG LINES OF SIGHT, VIEW- ING DISTANCES, ETC., FOR KEY VISTAS STOP Variables known at the end of Step 1: Q. IfZ, Zblock' xfi * From Level 1. t Different values can be determined for different trajectories and vistas. (a) Step 1: Description of the area and possible trajectories Figure 28. Logic flow diagram for level-2 analysis (see section 4.1.1) 124 START DEVELOP JOINT FREQUENCY DISTRIBUTIONS OF STABILITY, WIND SPEED, AND WIND DIRECTION TABULATE THE FREQUENCY OF METEOROLOGICAL CONDITIONS IN ORDER OF INCREASING DISPER- SION FOR WIND DIRECTIONS ASSOCIATED WITH POTENTIAL IMPACTS IDENTIFY THE DISPERSION CONDITION (az u) PARAMETER THAT CHARACTERIZES THE 1-PERCENTILE (^-4 DAYS/YEAR) WORST -CASE EVENT STOP Variables known at the end of step 2: oZ ; ut * This step is not necessary if the level-1 analysis shows C1 and C2 between -0.1 and +0.1. t Values can be determined for different trajec- tories and vistas. (b) Step 2: Specification of worst -case stable transport meteorological conditions (section 4.1.2.1) Figure 28 (Continued) 125 START DEVELOP JOINT DISTRIBUTION DATA FOR MIXING DEPTH, WIND SPEED, AND PERSISTENCE OF CONDITIONS IDENTIFY CLASS I AREAS BY DIRECTION AND DISTANCE FROM SOURCE CALCULATE THE PROBABILITY OF CLASS I AREAS BEING IMPACTED UNDER DIFFERENT WIND SPEED AND PERSISTENCE CONDITIONS n Values known at the end of step 3: utHmt TABULATE THE FREQUENCY OF METEOROLOGICAL CONDITIONS IN ORDER OF INCREASING DISPERSION FOR PERSISTENCE CONDITIONS RESULTING IN POTENTIAL IMPACTS ON CLASS I AREAS IDENTIFY THE LIMITED MIXING CONDITIONS WHm) THAT CHARAC— TERIZE THE 1—PERCENTILE (^-4 DAYS/YEAR) WORST —CASE EVENT) STOP * This step is necessary only if the level-1 analysis shows C3 to be greater than 0.1. t Although a single dispersion parameter u•Hm should be determined, multiple pairs of values can be determined at this step. For example, (2 m/s, 1000 m, and 4 m/s, 500 m) give the same value for u-Hm of 2000 m2/s. § Because of the dramatic variability in the type and level of detail of available meteorological data, this flowchart indicates only the general intent of steps necessary to specify the limiting diffusion parameter u-Hm. (c) Step 3: Specification of worst -case meteorological conditions for general haze§ (see section 4.1.2.2) Figure 28 (Continued) 126 START DETERMINE MEDIAN OZONE CONCENTRATIONS THAT CHARACTERIZE SEASONS OF CONCERN DETERMINE MEDIAN BACKGROUND VISUAL RANGE(S) THAT CHARACTER- IZE THE SEASONS OF CONCERN STOP Values known at the end of step 4: [031, rv0 (d) Step 4: Background atmosphere description (sections 4.1.3 and 4.1.4) 127 START DETERMINE PLUME :ENTERLINE-OBSERVER RELATIONSHIPS AN) TIME AND DAY FOR SPECIFIC SCEI4ARIOS DETERMINE AZIMUTHS, as, AND SCATTER- ING ANGLES (0) FOR LINES OF SIGHT DETERMINE OBSERVER -OBJECT DISTANCES STOP Values known at the end of step 5*: a' 0' ro' rp * There will be a number of values for each of the lines of sight on data and times considered. (e) Step 5: Determination of plume -observer geometries and specification of scenarios (section 4.2.1 128 START DETERMINE SIZE DISTRIBUTION PARAMETERS FOR PRIMARY PARTICU— LATE EMISSIONS (DG, 69, p) CALCULATE SCATTERING COEFFICIENT FLUX FOR PRIMARY PARTICULATE, Qscat=part CALCULATE WAVELENGTH DEPEN— DENCE OF Qscat-part CALCULATE [NOXI AND [N021 FOR EACH SCENARIO CALCULATE OPTICAL THICKNESS ATTRIBUTABLE TO NO2 (TNO, ) FOR APPROPRIATE WAVELENGTHS CALCULATE SULFATE FORMATION CON— TRIBUTION TO SCATTERING COEFFICIENT FLUX, Qscat—SO4, FOR EACH SEASON OF CONCERN (GENERAL HAZE ONLY) CALCULATE PLUME OPTICAL THICKNESS FOR STABLE TRANSPORT (?part) AND GENERAL HAZE (Taerosol) AS APPROPRIATE (f) Step 6: Calculation of worst -case impacts (Sections 4.2.2, 4.2.3, and 4.2.4) Figure 28 (Continued) 129 0 CALCULATE BACKGROUND ATMOSPHERIC SCATTERING CHARACTERISTICS, bextr bscatf bsp, and bR FOR APPROPRIATE WAVELENGTHS AND SIZE RANGES DETERMINE PHASE FUNCTION VALUES, p o,9), FOR SCATTERING ANGLES OF CONCERN FOR BACKGROUND, PLUME, AND GENERAL HAZE CALCULATE AVERAGE PHASE FUNCTION VALUES FOR BACKGROUND CALCULATE PLUME CONTRAST, CpLume CALCULATE REDUCTION IN SKY - TERRAIN CONTRAST, AC / INTER- PRET RESULTS OF LEVEL-2 ANALY- SIS FOR ALL ***..�CENARIOS -0.1 < CpLume < 0.1 and AC < 0.1 r STOP M (Concluded) Figure 28 (Concluded) lcplume) '— 0.1, or ACr >_ 0.1 MORE ANALY- SIS NEEDED 130 5 SUGGESTIONS FOR DETAILED VISIBILITY IMPACT ANALYSES (LEVEL-3) if the level-1 and -2 visibility screening analyses indicate the pos- sibility of adverse or significant visibility impairment, one may wish to undertake a more detailed analysis (level-3). Even if a source passes the level-1 and -2 screening tests, it may be advisable to analyze potential impacts in greater detail. More detailed visibility analyses may be needed in the following cir- cumstances: > When level-1 and -2 screening analyses indicate the possi- bility of adverse or significant visibility impairment. > When the potential costs and delays incurred in emissions source siting, -emissions control design, and regulatory approvals indicate that more detailed studies would be beneficial, regardless of the outcome of the level-1 and -2 screening tests. > If greater accuracy and definition are necessary, for example, to define the frequency of occurrence and the time of year of worst -case impacts. > If emissions are of a special nature, such as reactive hydrocarbons. In such cases one should use models that account for photochemistry (e.g., a reactive plume model with a complete photochemical mechanism). > When the appearance of the visual impact is a concern (that is, when considering what the worst -case discolored lYlume or haze will look like). > When the effect of visibility impairment on perceived scenic beauty in a class I area requires quantification, as when a cost -benefit study is performed. 131 > When area topography is complex, so that the assumptions made in the level-1 and -2 screening analyses are no longer appropriate, as when plumes are blocked, channeled, or trapped by terrain features. > When an emissions source that is being analyzed, or is similar to the one being analyzed, is currently operating. Under these circumstances, it would be desirable, especially if level-1 and level-2 tests indicate a poten- tially adverse or significant impairment, to supplement screening analyses with detailed impact analyses and with intensive and long-term monitoring of meteorological and ambient conditions; plume transport, diffusion, and chem- istry; and visual impacts in the potentially affected class t areas. > When the concern is with the cumulative impacts -of several emissions sources within a region. It is not the purpose of this chapter to provide step-by-step instructions for carrying out these more detailed analyses. Each separate analysis will vary with the specific circumstances. Instead, we briefly outline some important elements in such detailed analyses that the analyst may wish to consider. Indeed, further visibility model development may be needed for some problems. 5.1 FREQUENCY OF OCCURRENCE OF IMPACT As discussed in chapter 2, the frequency of occurrence of visibility impairment is as critical to the assessment of adversity or significance of impact as is the magnitude of visibility impairment. We can assess the frequency of impact occurrence by applying a computer model to all poten- tial combinations of the following factors: 132 > Emission rates. > Wind speed. > Wind direction. > Stability. > Mixing depth. > Plume dispersion, given a specific meteorological condi- tion. > Background ozone concentration. > Background visual range. > Precipitation. One might require 100 or more model runs to characterize adequately the magnitude and frequency of impact occurrence in some situations. Impact can then be summarized in figures or graphs, as shown in figures 29, 30, and 31 and tables 6 and 7_ Note that these examples were stratified by season to illustrate the seasonal dependence of impact and the fact that for this example the maximum frequency of impact occurrence is predicted in the winter season when class I area visitor use may be minimal. 5.2 APPEARANCE OF IMPACTS A further specification of the appearance of visual impacts may be necessary to supplement estimates of magnitude and frequency of occur- rence. The adversity or significance of an impact is dependent on the size of the area affected by a plume, as well as by the magnitude of dis- coloration or contrast reduction. A plume viewed from a distant location has a smaller visual impact than it would if viewed from a nearby loca- tion, even if the magnitude of discoloration is the same in both instances, because in the former situation, the plume affects fewer lines of sight (i.e., appears smaller). A 200-m-thick plume will subtend an angle of 1.2' when the observer is 10 km away, 0.5* (which is the angle subtended_ by the moon) when the observer is 25 km away, and 0.1' when the observer is 100 km.away from the plume centerline. 133 f A L 0 � 1 0 L 4 6 a., M I n av 6 0 5 10, days (a) winter t 15 20 25 days (b) Spring 1-A 1 AND 2 aI W Ir 2 a UN1T5 i 1-1 UNITS 1 AND 2 days days (c) Summer (d) Autumn Figure 29. Examples of predicted frequency of occurrence of plume discoioratien Perceptible from a class I area: number of mornings in the designated season with an impact greater than the indicated value. 134 days (a) Wi nter UNITS 1-4 'UNITS 1 AND 2 co 20 15 UNITS 1-4 UNITS 1 AND 2 10- UN 0 5 10 15 Zu days (b) Spring 25 20 ITS 1-4 UNITS 1 AND 2 5 0 25 9%0 `� _5 0 5 10 15 20 25 days days (c) Summer (d) Autumn Figure 30. Examples of predicted frequency of occurrence of haze (visual range reduction) in a class I area: number of afternoons in the designated season with an impact greater than the indicated value. 135 70. too. So. W N > 30. xo. W � 10• n_ 1.3 1.2 s 1.0 W d.• e, 0.7 0.6 0.5 0.4 0' 0 -0 in s -0 s C -0 -0 -0 -0 -0 40 NSSUAED TIEMIMB MCK6113IIY0: 1-CLEAR SKY. 2-WHITE 38ACT. - ---- -- --- - -- -- -., K.. .s .1 .0 .. »..... _............................... _............ ...... .4 A .0 3S.0 30.0 W 2S.0 ' 20.0 W 1S.0 10.0 O.O L 0 45 9D 13S 180 :2S 270 3I' '°? RIIMUTM ANOL91MOREESI (a) 1 m/s wind speed, stable condition, 348.8 degree wind direction Figure 31. Examples of calculated plume visibility impairment dependent on wind direction, azimuth of line of sight, and Viewing background. 136 70.0 960.0 60.0 10.0 w 30.0 20.0 r 10.0 6.0 ASSMO TICKING &4"GREMD: /-CLEAR SKY. !-WITS UJECT. $-CAST ldJECT. 4-*LACR 89JECT. 0 4• 0 0 a a 0 .° 0 0 0 0 .tee » c :c v ca � saRj7MUTM ANGLEIOEfiREE31 '-_ (b) 1 m/s wind speed, stable condition, 11.3 degree wind direction Figure 31 (Continued) 137 T 91 r s� sl n W RISUPIEO VIEVING 9KKGkNM: 1-CLE Mt SKY. 2-UNITE ft JECT. v wi 135 Ito =S 270 SIS 360 NOWTH NMEIMORKS) (c) 1 m/s wind speed, stable condition, 22.5 degree wind direction Figure 31 (Concluded) 138 TABLE 6. EXAMPLE SUMMARY OF THE FREQUENCY OF OCCURRENCE OF POWER PLANT PLUME DISCOLORATION PERCEPTIBLE FROM A CLASS I AREA' Number of Mornings with AE(L*a*b) Greater than Indicated Value 2.5 5 10 Units Units Units Units Units Units Season 1 and 2 1 through 4 1 and 2 1 through 4 1 and 2 1 through 4 Winter 4 6 2 3 < I 1 Spring 1 2 < 1 1 0 0 Summer 2 3 1 1 0 0 Fall 3 5 1 2 <1 <1 w "' Annual total 10 16 4 7 1 < 2 .p 0 TABLE 7. EXAMPLE SUMMARY OF FREQUENCY OF OCCURRENCE OF INCREASED MAZE (VISUAL RANGE REDUCTION) IN A CLASS I AREA DUE TO POWER PLANT EMISSIONS Number of Days with Visual Ranqe Reduction Greater than Indicated Value 5% 10% 15% Units Units Units Units Units Units Season 1 and 2 1 through 4 1 and 2 1 through 4 1 and 2 1 through 4 Winter 9 10 3 5 0 1 Spring 3 3 1 2 0 < 1 Summer 4 4 0 1 0 0 Fall 5 5 2 3 0 1 Annual total 21 22 6 11 < 1 2 Also, the appearances of the plume will change depending on the wind direction and the viewing background distance and coloration. Thus, one has to know the viewing background. and the vertical and horizontal (azimuthal) extent of the plume to characterize the visual impact com- pletely. The appearance of plume discoloration and contrast reduction can be quantified using calculations of the magnitude of impact as a function of vertical and horizontal orientation of the line of sight, or by specifying the angle subtended by a plume. Alternatively, one can display impact using > Black -and -white plume -terrain perspectives (see example in figure 32). > Color graphic displays, such as those developed by the Los Alamos Scientific Laboratory (Williams, Treiman, and Wecksung, 1980). > Color photographs of plumes or haze similar to the condi- tions being analyzed. 5.3 IMPACTS ON SCENIC BEAUTY There is some recent evidence (Latimer, Daniel, and Hogo, 1980) that the scenic beauty of some areas may not be adversely affected by reduc- tions in visual range, though the scenic beauty of other areas may be very sensitive to visual range. There have been no studies to determine the scenic beauty sensitivities of class I areas to plume visibility impair- ment (i.e., discoloration and contrast reduction). 141 A N Figure 32. Example of black and white plume -terrain perspective. In certain detailed visibility impact assessments, it may be desirable to quantify the sensitivity of potentially affected areas. For example, days of visual impact of a given magnitude might be translated into days of a given decrease in class I area scenic beauty (as perceived by an observer). This would be an essential first step in establishing the aesthetic benefits of a given emissions control action. 5.4 IMPACTS OF EXISTING EMISSIONS SOURCES Although the primary purpose of visibility computer modeling and the screening analysts techniques presented i n this workbook is the prediction of future impacts of proposed new sources, these analytic tools can also be used to eyaluate the impact of exi.sti,ng sources. However, because these techniques are not required to be routinely exercised in any regulatory program applicable to either new or existing sources, mon- itori,ng techniques, especially visual observations (either ground based or with aircraft), are likely to be the first step in identifying the origin of visibility impairment caused by a single source or small group Of sources. EPA has published the document "Interim Guidance for Visibility Moni,tori,ng," EPA-450/2-80- 082, which contains technical considerations Involving the design of visibility monitoring programs, selection of instrumentation, duality assurance and data processing. Instrumental monitoring methods for visibility are not yet routinely required in regulatory programs for visibility protection but the guidance does provide substantival information regarding available visibility monitoring methods Presently in use,. It is recommended that a minimum of one full 143 year of monitoring be conducted for visibility impact analyses of major point sources. In addition to this long-term (one year or longer) measurement/ analysis program, it may be desirable to design and implement several short-term, intensive measurement programs to compare measurements and model predictions of plume transport, diffusion, chemistry, aerosol forma- tion, and the resulting optical effects. 5.5 REGIONAL IMPACTS In many cases, the visibility impairment caused by a single emission source may be small compared to the cumulative impacts of many natural and man-made sources in a region. However, the visibility impairment of that single source may contribute to a significant regional haze. It is beyond the scope of the first phase of visibility regulations and of this workbook to address such cumulative, regional impacts. Regional visibility models and measurement/analysis programs will be required to assess the extent of existing regional visibility impairment, to determine the relative contributions of various emissions sources to that impairment, and to design and implement effective emissions control 144 on a regional scale (if possible) to restore and protect class I area visibility. 145 APPENDIX A CHARACTERIZING GENERAL HAZE One of three parameters is customarily used to characterize general atmospheric haze: > Visual range > Extinction coefficient > Sky/terrain contrast. Each of these is an equally valid means of quantifying atmospheric haze. Since the eye/brain system perceives the environment through color and brightness contrasts in various objects such as landscape features, the sky/terrain contrast is the most fundamental of these three parameters in terms of visual perception. However, contrast may not be the most appropriate means of describing haze, because one can have a large number of contrast values for different landscape features if such features are at various distances from the observer and have different intrinsic contrasts. Thus, in many situations extinction coefficient and visual range are simpler and more useful measures of atmospheric haze than is contrast. The relationships among these physical measures of atmospheric haze are discussed in more detail in the following subsections. A.1 WAVELENGTH DEPENDENCE It is important to note that each of these three parameters depends on the wavelength of light (a) to be considered. Since the light - scattering properties of the atmosphere are a function of wavelength, each Of these three atmospheric haze parameters is likewise a function of wave- 147 length. For -example, Rayleigh scattering by air molecules is proportional to X-4, and Mie scattering for a typical aerosol is proportional to a-n, where generally 0 < n < 2. The spectral reflectance of a landscape feature will also be a function of wavelength if the landscape feature is not white, gray, or black. Because of this wavelength dependence, we must be specific when we define visual range, extinction coefficient, or contrast. Many optical instruments and the human eye respond to a broad wavelength band; others are narrow -band instruments. Indeed, some of the discrepancies among various measurements of atmospheric haze (in which such techniques as nephelometry, te.lephotometry, photographic photometry, and human observation are used) are due to the different spectral sensitivities- of each instrument. Throughout this discussion we will assume that contrast, visual range, and extinction coefficient are defined in equivalent ways with respect to wavelength. For example, we can define these parameters for a narrow wavelength band at 0.55 tm, the center of the visible spectrum, or a broader band with some characteristic wavelength. This discussion does not depend on which wavelength band is considered, but the three parameters must be defined for similar spectral bands. A.2 THE CONTRAST FORMULA For a homogeneous atmosphere, contrast and extinction coefficient are mathematically related by the Lambert -Beer law for contrast, as follows: Cr/Co = e-bextro 9 where Co is the intrinsic contrast of a landscape feature against the sky (as observed near the feature), Cr is the apparent contrast of the land- scape feature observed from a distance ro, and bext is the extinction coefficient of the atmosphere through which the terrain is observed. 148* Using Middleton's (1952) definition of visual range, we can also relate visual range to contrast and extinction coefficient. Visual range is defined as the distance ry such that Cr/Co = 0.02 = e-bext ry (A-2) Note that by solving for ry we have the well-known Koschmieder rela- tionship, ry = _ �Px�(— �6 0.02) _3.9.12 (A-3) ext ext These relationships can be extended to nonhomogeneous atmospheres if we define an appropriate average extinction coefficient over the line of sight of interest. A.3 QUANTIFYING INCREASES IN ATMOSPHERIC HAZE When the impact of a proposed source or combination of sources on atmospheric haze is of concern, the relevant question is: what is the resulting change in atmospheric haze conditions compared with that which would occur otherwise? For example, one might be concerned with the increase in haze that results from certain emissions on a particular day, on the worst day in a year, or on an average day in a year. Alterna- tively, one's concern might be the shift in the seasonal or annual fre- quency distributions of haze conditions. We can quantify increased atmospheric haze by one of four parameters: > Increased extinction coefficient (Lbext) or fractional increase relative to a given background (Abext/bextO)• > Decreased visual range (-erv) or fractional decrease in visual range relative to a given background (- Arv/rv0)• > Decreased sky/terrain contrast (-ACd or fractional decrease in contrast relative to the contrast that would occur for a given background (- eCr/CrO)- 149 > Plume optical thickness ( =plume) the integral of extra extinction (bbext) along the line of sight through the plume. The remainder of this discussion describes these four parameters and the relationships among them. There are two general classifications of spatial distributions of increased extinction (see figure A-1): > Nonuniform distributions over a portion of the line of sight (e.g., a plume). > Uniform increase over the entire line of sight (e.g., regional haze or situations in which the plume width is large compared to the visual range or to the line of sight). The impact of a plume is best described by the plume optical thick- ness (Tplume), whereas the regional impact is better described by extra extinction (Abext)- A.3.1 Plume Impacts Plume optical thickness is defined as the integral of the extinction coefficient over the line of sight: Tplume = bextdr fp 1 ume (A-4) This optical depth can be converted to an average extinction coefficient over some line of sight at distance R: Eext - plumeA (A-5) The distance R may be the distance between the observer and a particular landscape feature (ro) or the visual range distance (rv), depending on the 150 it Obse Plume of extra extinction (a) Nonuniform distribution of extra extinction (plume impacts)* (b) Uniform distribution of extra extinction (regional haze or dispersed plumes) Figure A-1. Two types of spatial distributions of extra extinction. re problem being addressed. For example, if one is concerned about the con- trast loss in a landscape feature at a given distance from an observer, it is appropriate to use the distance to that feature as the value for R. However, if several landscape features at different distances are involved, or if one does not know the distance to a landscape feature, it is appropriate to use the visual range distance ry as the value of R. If we do the latter, we obtain a rather simple and elegant formula for the visual range reduction caused by a plume. The total average extinction coefficient of the background atmosphere and the plume together is bb _ Tplume (A-6) ext ext0 + ry ' where bext0 is the extinction coefficient of the background atmosphere with visual range rv0s, Tplume is the plume optical thickness, and ry is the reduced visual range as a result of plume impact. The reduced visual range caused by plume material can be determined by substituting equation (A-6) into the Koschmieder relationship, equation (A-3), and solving for rv. The result is ry = rv0 (1 - plume/3.112) (A-1) The fractional reduction in visual range is simply rv0 - ry = 'Plume (A-8) rv0 Note that equations (A-1) and (A-8) are not valid for cases in which the plume is opaque (e.g., one cannot see beyond the plume) or is significantly discolored. For such cases a more detailed visibility model or the formulas provided in the text should be employed. Note that the fractional reduction in visual range for this plume situation is independent of the background visual range (rv0). 152 A.3.2 Regional Haze Impacts For the second case, in which there is a uniform increase in extinc- tion coefficient (Abext), the fractional decrease in visual range is not independent of the background visual range: _ 3.912 3.912 v extO + ext 3.9127rvo + Ab ext ry = (1/rvO + &ext /3.912)-1 1 rv0 _ ry - 1 - 1 + (rv0) (Abext) _ rv0 . -1 +Ab � t extO f (A-9) (A-10) (A-11) A.4 THE EFFECT OF INCREASED HAZE ON THE CONTRAST OF LANDSCAPE FEATURES The sensitivity to increased haze of the sky/terrain contrast of a landscape feature observed from a distance ro can be evaluated by differentiating equation (A-1): acr = -rC a bextro (A-12) abext o The observer -terrain distance ro at which the greatest change in con- trast per unit change in extinction coefficient occurs can be determined by differentiating equation (A-12) again with respect to r, setting this derivative to zero, and solving for r. This distance is found to be ro = bext-1 = 0.26 rvO (A-13) 153 On the other hand, the greatest fractional change in contrast per unit change in extinction coefficient occurs with the most distant visible landscape features. This can be shown by rearranging equation (12): 1 3Cr �r text = -ro . (A-14) Thus, depending on whether the human observer detects changes in haze conditions as a result of fractional or absolute changes in contrast, landscape features` at distances of the full visual range or about one- fourth the visual range will be the most sensitive perceptual cues, respectively. The change in contrast (aCr) of a landscape feature resulting from a given change in extinction coefficient (dbext) can be evaluated by integrating equation (A-12): oC = -C e-bextoro 1 - e-�extro r 0 = -Cr 1 - e Abextro If the change in extinction coefficient (ebeXt) is due to a plume between the observer and the landscape feature, then the change in con- trast can be calculated as follows, assuming that the plume does not sig- nificantly discolor the horizon sky: eCr = -Cr 1 - e Tplume (A-16) 154 With the following transformation of variables, we can relate the change in sky/terrain contrast to extinction coefficient, plume optical thickness, and visual range reduction in a more lucid manner: fr = ratio of observer -terrain distance ro to background visual range = ro/rvo f (A-17) fb = fractional increase in extinction coefficient _ text (A-18) eextO fv =_ fractional decrease in visual range (A-19) rvo - ry - r ' v0 With these transformations we can write the equations for the rela- tionships between contrast change and other visibility parameters as follows: Extra extinction: dCr = -Cr 1 - exp (-3.912 frfb) , (A-20) f Visual range reduction: aCr = -Cr 1 - exp -3.912 fr v ' V)] Plume optical thickness: ACr = -Cr 1 - exp(- Tplume) - (A-21) (A-22) 155 The value of Cr is a function of the intrinsic contrast (CO) of the landscape feature and the distance to the feature relative to the back- ground visual range (fr): Cr = C0exp (3.912 fr ) (A-23) The change in sky terrain contrast (ACd as a function of increased extinction, reduced visual range, and plume optical thickness is plotted in figures A-2, A-3, and A-4, respectively. Sky/terrain intrinsic con- trast (CO) was assumed to be -1.0, which is appropriate for a black object. The effect of observer -terrain distance on these relationships is shown by plotting curves for r/rvO = 0.1, 0.26, 0.5, and 0.75. The maximum decrease in contrast for a given increase in extinction or decrease in visual range occurs for landscape features at 26 percent of the visual range, as we noted earlier, while the maximum contrast decrease due to a plume occurs for the closest landscape features. A.5 SUMMARY The relationships among the parameters used to characterize increased atmospheric haze are summarized in table A-1. 156 0.14 0.12 a 4J CA L 0.10 c 0 U Zn 0.04 a� i v a, 0 N I ro /ram = 0.26 .1 - 0.5 0.75 i a Figure A-2 . 0.1 1.0 10.0 Fractional Increase in Extinction Coefficient (Abext/bext0) Change in sky/terrain contrast as a function of fractional increase in extinction coefficient for various observer -terrain distances. r 1❑ 1 10E c.s a 4J V 0 b i 4j C O U C Q b L i F-- ~` 0 c a 0. to a) L C1 q! 1 m .14 .12 v ro /r = 0.26 0.1 a .10 '0.5 .08 06 0.75 04 02 0 0.1 0.2 0.3 0.4 Fractional Decrease in Visual Range (-orv/ry ) 0.5 Figure A-3. Change in sky/terrain contrast as a function of fractional decrease in visual range for various observer -terrain distances. CI7 0.1 0 0.11 b L +j c 0 U C 0.G •r b i L 0.0 Y N 41 2 r. ro /rvo = 0.1 0.26 0.5 0.75 0 0.1 0.2 0.3 0.4 0.5 Plume Optical Thickness (Tplume) Figure A-4. Change in sky/terrain contrast as a function of plume optical thickness for various observer -terrain distances TABLE A-1. SUMMARY OF RELATIONSHIPS AMONG PARAMETERS USED FOR QUANTIFYING INCREASED ATMOSPHERIC MAZE* To Convert From To: T lume fb fv fc Tplume -- fb R bextO 3.912 fv - Zn (1 - fc) l ume fv nn (1 - fd fb -- - ext0 � tV r TT-ppl-umefb - In (1 - fc) fv �I2- 1+ tb --3.912 T r- n - c fv fc 1 - exp (-Tpl urns } 1 - exp (-3.912 frfb ) 1 -exp -3.912 f r -i---'1'-- -- Nomenclature plume .-a Tplume `= optical thickness of plume =f b dr ext. fr a ration of observer terrain distance ro to background visual range rv0 fb = fractional increase in extinction coefficient = abe xt extO fv a fractional decrease in visual range =-arv/rv0 fc =- fractional decrease in sky/terrain contrast =-ACr/CrO R = line of sight averaging distance bext0, rvo, Cro = extinction, visual range, and contrast used as reference baseline for increases in haze. * These formulas are valid only for cases in which the plume material does not significantly discolor the horizon sky tsee section 2 of the text). 0 APPENDIX 8 PHASE FUNCTIONS Data for the aerosol phase function [p( a,e)] are provided in this appendix as a function of these factors: > Aerosol size distribution with different mass median diameters (DG), all with a geometric standard deviation ag of 2.0. > Wavelength X = 0.40, 0.55, and 0.70 un. > Scattering angle 0 (0* < A < 180°). 161 DG = 0.1 um a=0.4vim 0 0,0 S,5738E400 9200 40tSSE Ot Z,0 5:S565E+00 9480 4,22b1E.p1 4g0- 5,5052E+00 9600 40056SE.01 6,0 5,4219E+0o 0890 349061E•OI 8,0 S3094E+00 10000 30729E.01 logo 5,1714E+00 102;0 306558E•O1 Ia10 5:0121E+oo i040 3,5536E•Ot 1490 4,8357E+00 106:0 3,4653E.01 1660 416462E+00 10840 313899E •01 1800 4,4474E+00 110.0 3,3264E.ol 2.0,0 4,2428E+00 11260 3.2741E■01 22,0 4,0355E+00 11400 392319E•n1 24,0 3:8278E+o.o 11660 3,1992E•ot 26*0 3,6221E+00 11A.0 3,1752E•Ot ..2810 3.4199E+00 12060 3,1589E.pt 3010 3,2227E+00 12200 3,1499E.p1 3290 340316E+oo 124.0 301473EMO1 3400 2,8472E+00 12640 3,1508E.01 3690 2,6702E+00 12890 3.1598E-01 3800 29SO11E+00 13000 3,1738E-01 4090 2,3401E+no 11290 3jl925E•01 4290 4490 2,1873E+00 2:0429E♦00 13466 13600 3,2154E•O1 3,2420E+01 4690 4810 1,9068E+00 1:7788E+00 13AOO 14090 3.2719E-01 3,3043E•O1 5090 5210 1,6589E+00 1,5467E+0o 142,0 14400 3,3390E.01 3,3753E.03 5490 5600 1,4419E+0o 1,3442E+0o 14600 148 0 3g4l30E•-Ot 3,4516Ew41 5800 6090 1,2533E♦Oo 1,1687E+00 lSO 0 15Z�p 3�49p9E.pt 3,5307E-01 62,0 64.0 t00902E*00 1�0175Et00 154�0 156�0 3,5709E-01 3,6113E-01 66�0 68�0 9�5022E.01 8�8806E•01 1S800 16000 3,651AEw01 3,6922E-0t 70.0 7200 803073E•01 717791E.01 16200 3,7323E-0i 7460 76Z930Ew41 1640 � 166�� 3,7719E-01 3,8110E-01 7600 7gso 6�8463E•01 6,4363E-01 16800 17090 3,8490E.01 8000 8290 6�0607E•01 5.7172Ew01 1 ? 0 388854E-Oi 3, 189E.01 8846,0 00 5,40399E-01 5�118 E•01 174:0 176 0 3.948lE•O1 3g9710E.01 88lp 9090 a 8b03E•01 4.6264E.p1 17A�p 18060 3@9856E•01 399906E.01 162 0 P7�0 010 4• 0 E+00 210 4,4799E+do 490 4,4483E+00 60 4,3967E+00 8:0 4,3263E+00 10,0 4,2389E+0o 12,0 4,1367E+0o 1410 4,0217E+00 16,0 3,8963E+00 18,0 3,7627E+00 2000 3,6228E+0o 22,0 3,4787E+0o 24,0 3,3319E+0o 2690 341840E+oo 2810 300363E+o0 3000 2,8898E+00 3210 2,7455E+00 3490 2.6042E+00 3690 2,4666E+00 3840 2,3331E+00 4000 2.2043E+00 4290 2,0804E+00 4490 1,9617E+00 4660 1,8482E+00 4840 1,7401E+00 5000 1.6373E+00 5290 1,5398E+00 S440 1,4476E+00 S600 163606E+00 so$o 1,2786E+o0 b080 1.201bE+00 6210 1.1294E+00 6490 1,0619E+00 6600 9,9882Eo01 6890 9.4009E•o1 7080 8,8549E•01 7290 8,3485E■01 7400 7.8799E•01 7660 7*4473E•O1 7890 7*049OE•O1 5000 6.6833E*01 82,0 60346SEDOI $400 6,0429E•OI 6600 5.7650.2•01 8880 SoSl30E•Ol 9010 5.2857E•01 DG = 0.1 um A = 0.55 um 0 Pao 9200 S,0814E•Ot 94,0 41898SESOI 9660 4,7367E.Ot 9800 41593BE001 10000 404689E.01 10200 4,3609E■Ot 10400 u,2685E.01 10690 40 908E.01 10800 491267E•01 11040 4,0754E.Ot 112.0 4,0357E.01 114.0 480070E•Ot 116.0 3,9884E•01 118,0 3,979JE•Ol 120,0 3,9784E•01 12200 3,9854E.Ot 124.0 31,9996E•01 12600 490202EoOt 12800 4,0466E•01 13000 4v0781E•0t 13290 441142E.Ot 13460 461544E•01 13680 40198IE•0t 139.0 4.2447E•01 140.0 4,2938E•Ot 142.0 4,3447E•Ot 14400 4,397OE•Ot 14600 464501E•01 14800 495035E•Ot 15000 495S68E.01 1S200 46609SE001 15490 496612E•01 15600 4.7117E.Ot 15800 497b08E•o1 16090 4,8083E•Ot 16290 4,8539E.Ot 164410 498975E.o1 t66,0 40388E•O1 16800 419772E•Ot 170,0 500120E•Ot t7200 5,0424E•Ot 17490 S I OOSE.01 1760 S,OS62Ew01 176:0 So0979E•01 18060 511018E•01 163 DG = 0.1 um a 0.7 pm p P(a,0) 0 9200 S,S69uE.01 2:0 398103E+00 9490 ,3994EwOt 578RbE+00 4.0 3� 96.0 5.250tEw01 6.0 3,7529E+00 9800 5.1202E•Ot 840 3.7039E+00 100,0 5,0087E•ot 1000 3,6427E+00 10200 469145E•01 1200 3,5703E+00 10400 428365Ew0t 140 3,4881E+00 106.0 4,7736E•01 16:0 1880 3,3974E+00 3,2995E+Oo IOR,O 110,0 Q 7250EwOt 4,689bE.01 2010 39t959E+Ou 112.0 406665Ew01 2280 3,0878E+00 11400 4,b5G7E•Ot 2480 2,9764E+00 11690 46653QE•Ol 26.0 2,8629E+oo 118,0 u 96618E.Ot 28,0 2y7481E+00 120,0 4.6789E•Ot 3090 2,b330E+00 12200 4,704OE•01 3240 2,5184E+00 12400 4,7363E.Oi 3400 294049E+00 1.2680 4177SOEwO1 360 2,2931E♦00 128�0 488194E•Ot 38:0 2,1835E+oo 130,0 408669E•ot 4010 2,0766E+00 .13200 499227Ew01 11290 149726E+00 13400 499802E•Ot 4a00 1,8720E+00 13600 5.0409EwOt 46.0 1,7749E+0o 13800 5,104OEw0t 4890 1�b8t5E+00 14000 5,1689E.01 5090 1,5919E+00 14200 5,2352EwOt 5200 1,5063E+00 144,0 5,3022E.0! 14600 5,3693E•01 560Q • !•3471E+00 • 14890 5,4361Ew0t 58,0 1,2735E+00 150.0 5,502IE•0i 6000 6200 1,2039E+00 f,t382E+00 152,0 154:0 5,S668E•o1 5,629REw0! 6410 6610 1,0763E+00 1,0182E+00 15690 15890 596907E•Ot 597492E.0t 68.0 70.0 9,6382Ew0! 9,1298E•O1 !b00 162:0 5,8049E•Ot 5.857SE•Ot 7290 7490 8,b561E•O1 8,2159E.01 164,0 tb6.0 5,90615Ew0! 5,9516E.01 7610 78,0 708082t•01 7,4317E.01 168,0 170 0 7 5,9922E•Ot 02 wOt 6� 77E 80 O 82.0 7 0852Ew01 6•7b7bE901 172.0 b.4578E.01 84,0 6,4776E•01 174.0 176,0 6.0818E•01 6,0993E•0t 86,p 88,Q 6,2139E.01 5�g754E.01 178.0 6,1100Ew01 9090 S9761OE•01 180,0 6,1136E•0! 164 DG = 0.2 um A = 0.4 um 000 e�e�eE+00 zso 898449E*00 490 816686E*00 6s0 804439E+00 $so 8.1287E+00 logo 767611E+00 12s0 703576E+00 14.0 609323E+00 1690 6*4970E*00 1890 6,0617E+00 20s0 S.6342E+00 2290 5.2205E+00 2490 4:8250E+00 26s0 404501E+00 28:0 400972E+00 30.0 307667E+00 32.6 3.4582E+00 3410 3ot710E*Oo 3640 204046E+00 3890 2.6581E+00 4090 2,4307E+00 4290 ?02217E#00 4490 2,0301E+00 O6s0 108551E+00 4800 106957E+00 Soso 1,5509E+00 5260 1.4195E+00 S4.0 1,3001E+00 5680 1.1915E+00 5800 1.0927E+00 60.0 110029E+00 62.0 9s2119EwOl 64s0 814711Ew01 6640 798003Ew01 6860 7*1940E.ol 7010 606464E.01 7200 60514Ew01 7440 507028E.01 76s0 5s2950E.01 0 . 4.9235Ew01 Soso 4�58S1E.01 8200 4s2775E•41 84�10 309988E.01 56.0 3.7470E•01 88s0. 30519SEDOI 90.0 3.3147Ew01 p Pao 9290 3.1297E•Ot 9400 9.9629Ew01 9680 2.8134EwOt 9800 216801Ew01 10000 2.5617EwOt 10200 2s45bSE•01 10400 2s3631Ew01 10690 2.2801E.01 10860 2.2070E.01 11000 291436ED01 11200 2.089bEw01 11480 2e0444EeOl 11690 210073Ewot 118.0 169775Es01 12090 199536EwOt 12200 1 s935SEw01 12460 1.9219Ew01 12680 18913OEw0t 12800 1.9091EWO1 13000 199105E•Ot 132.0 1.9176E•Ot 13400 1193o0EwOt 136*0 1.9473E90.1 138:0 1.9687Ew0! 140,o 1.9933E•01 14200 2s0198EwOl 144*0 2.0469E•0i 14600 22074SEw01 14890 2s101OEw01 i5060 2sl28OEw01 152s0 2s1556E•01 154:0 2118V2EwOt 15680 2s2138Ew01 15880 2.2446Ew01 16040 2.2767Ew01 16260 2.3111E.01 16460 293492E.01 16600 2.3933Ew01 16800 2s445SE•01 17000 2o5079Ew01 1720 2.5777E•Ot 174:0 2s6495Ew01 17690 2,7139EwOt 17890 2.7592E.01 18000 2.7757E001 165 DG = 0.2 um a = 0.55 um 0 P(X,O) 0 P�� 6;0 702070E+00 9200 3,6T80E.0! 2,0 701747WO 9490 314984E-01 400 7,0798E+00 9600 303372E-01 600 6,9281E+00 98,0 301930E•01 ORO 617280E+00 10000 3,0644E-01 1040 604889E+00 10200 2.9500E•Ot 1200 602203E+00 104.0 2,8489E-01 1400 509309E+00 1Ob00 2,7601E-01 1600 506282E+00 10800 206825E•01 1800 503189E+00 11000 2,61S3E.0i 2000 500084E+00 11200 2,557bE•01 2200 407009E+00 11400 2,5088E-01 2410 40400.lE+00 11600 204684E-0! 260 4,1084E+00 11800 2,43b1E•01 28:0 308278E+00 12000 294114E•Ot 3000 305597E+00 12200 203935E-01 32,0 303048E+00 124.0 2,3818E•ol 34 3,0638E+00 2,8370E+00 1 6:0 235E-pp36,$ :701 3800 20bZ45E+00 .13000 203790EwOt 4060 204261E+00 13200 203876E-01 4200 4460 2,2415E+00 200703E+00 13400 13600 2,4008E•01 2t4186E-01 4600 4860 1,9117E+00 107650E.+00 13800 14000 224407E•01 204666E-Q1 solo 1,6294E+00 14200 204959E-01 S200 105042E+00 14400 205276E•Ot S400 5640 103885E+00 1 2819Etf10 146 0 . !4A•0 205609E-01 205947E•O1 58;0 1,1837E+00 15000 206280E-01 0000 o200 i,0935E+00 100108E+00 15200 l5400 20bbO5E-Ot 20b920E•Ol 6400 b600 90351SE.01 806599E•O1 15600 15800 207232E-Oi 207546E-01 0860 7000 800278E•O1 704500Em01 16000 1b200 Z,7874E -Ol 7200 7400 609220EM01 6:4401E•01 16400 2982ZbEw01 218612EU01 7600 7800 600011E-01 506019E-0! 1660o 16800 209037E•oi 209502E-01 solo 5200 542396E,01 409110E-01 17000 172 0 2 999uE•01 3,0491E-01 8400 0600 4#6131E•01 493433E•ot 174.0 176*0 3,09S7E•0! 3,1347E-01 Oslo 9060 400988E•01 388777E•01 17800 18000 301608E•O1 3,17o0E.o1 166 DG = 0.2 um 010 691113E+00 at0 600896E+00 490 600257E+O0 boo 599223E+00 890 517839E+o0 1000 5l6lSbE+00 129d S94230E+00 410 i6jo 512116E+00 419866E+00 lat0 4,7525E+00 2040 4.5137E+00 2290 4,2736E+00 2410 490352E+00 2600 3..6008E.00 2860 305724E+00 3090 3.3513E+00 3290 3,1384E+00 3410 2.9346E+00 3690 2,7402E+00 3890 2t555bE+00 4090 2.3809E+00 4200 2.2163E+00 4460 290615E+00 4600 119164E+00 4840 1.7809E+00 solo 1.6546E+00 Sato 1.5370E+00 5400 1,4277E+00 5600 1.3264E+00 Sato 192325E+00 6090 t91456E+00 6290 1.0652E+00 6490 919108E.01 6600 992277E-01 6810 BOS991EoCl 7090 89021SE-ol 7210 794910E•ol 7400 710043E-01 7690 6t5580E•01 7660 6.1491E-01 4090 507751E001 6290 514335E-01 8440 511224Ev01 8600 4.18397E.ol Soto 415834Ew01 9090 493514F•O1 a=0.7um 0 P(ate) 92.0 4/14ziEvOt 94.0 3,953SE•oi 9690 3,7851E-01 48.0 39634SE•Ol t00t0 3,5014E-01 10210 3,3838E-ot 10440 3,2806E-01 10600 3,1907E.01 108,0 391132E.ot 11090 3,0471E+01 11200 2,9917E-01 ti4,0 2,9403EwOl 11610 219099E*01 11890 2,8820E.01 12AGO 2,8616E.01 12200 2,8481E•O1 12490 209409EVOI 12600 2,839SEv01 12800 2,8436E-0t 13090 298528E-01 132,0 208669E.01 13400 298852E•01 13690 299075E-01 138,0 229331E.ot 14000 29961SEW01 14290 299922E-01 14480 3,0247E•Ot 14690 390585E-01 148,00 3,0931E-01 15000 3,1283E-01 152,0 3,1642E.Ot 15490 3,2006E.01 156,0 3t2375E.Ot 15890 3,2751E-Ot 160,0 3,3132E-01 16200 3,3519E-01 16U,0 3,3911E.01 16640 3,4309E-01 16800 3,4708E•O1 17000 3,5104E-01 172�0 3,5483E-01 174:0 3,5826E-01 176�0 3,6103Eo01 178,0 396286E.01 18060 3,6349E.01 167 DG = 0.3 um x=0.4um Q ao 000 1,1835E+01 2,0 1.1714E+01 4.0 1,1377E+01 6.0 1,OB78E+01 8t0 1,0274E+01 logo 9,6110E+00 1260 8.9228E+00 14.0 8,2342E+00 1600 7,5621E+00 18t0 609175E+00 2060 6,3078E+00 22.0 5,7376E+00 24,0 5,2096E+00 2b,0 4,7243E+00 2890 4,2806E+00 3090 3,8764E♦00 32.0 3,5088E+00 34.0 3.1747E+00 3600 2,8708E+00 3800 215944E+00 40,0 2.3434E+00 42.0 2,1162E+00 4460 1.9112E+00 4610 1,7273E+00 4890 115631E+00 Solo 1,41b7E+00 5210 102859E+0o 5490 1,1685E+00 5660 1,0628E+o0 Seto 9,6739Ew01 60.0 8,8139Ew41 6200 8,0385ElO1 6410 7,339BEwo1 66t0 6,7132E.O1 bd,0 691562E*O1 70,0 S,b656Ew01 72.0 5,232SEwOl 7400 498451EwOl 7600 4,4898Ew01 7800 4,1598Ew01 B0,0 30549Ew01 B2t0 3,5785Ew01 84.0 3,3339Ew01 6690 3sl202E•01 Seto.. 9010 299315Ewo1 2, 7601 Ew01 Q pao 92f,0 2.6002EoOl 9400 2.4515Ew01 96.0 2,3172Ew01 9840 2,2005EwOt 100.0 2,1009EwOt 10200 2.0149Ew01 10400 199381Ew01 106.0 1.0676E.01 10890 1,803OE•Ot 11000 1.7459E•01 112.0 196979Ew01 11400 1.6594Ew01 11600 19629UEw01 118.0 1.6066Ew01 1ZOt0 1.S893Ew01 122.0 1.5764E+01 12400 1,5674Ew01 126.0 1.5b26Ew01 12800 1*5631Ew01 130*0 1,5701Ew01 132,0 1.585OEwOt 13400 196084E•01 136.0 1.6402E•Ut 13800 196786Ew01 14060 1.7211Ew01 14200 147658EsOl 14480 198115E•01 146,0 1285e9Evot 14060 119003Ew01 15000 1.9398Ew0t 15200 199739Ew0t 154.0 2,0027E•0t 15600 2g0289Ewot 1S8�0 210S6oEw0t 1b0.0 2.0864EwU1 16240 2.1207Ew01 164.0 2 0 589EwOt 166*0 2,2051Ew01 16800 2,2687Ewo1 17090 2,3613Ew01 17290 2.4884E■01 17400 296418Ew01 17690 2.7965Ew01 17800 20148Ew01 180.0 2.4596E901 DG = 0.3 um 0 pa0 coo 9*4013E+00 2,10 9.33$9E+oo 460 901589E+0o 6.0 8,8794E+00 860 805233E+00 10.0 a i127E+oo iZ.O 7:6671E+oo 14.0 7.2023E+00 14�0 6.7311E+oo 18.0 602631E+00 2060 598OSbE+00 2200 5.3634E+00 2poo 4#9418E+00 2660 4G5419E+00 28,10 4l1655Et00 3Q�0 368135E+00 32.0 3.4862E+0o 3460 3.1834E+00 36.0 2.9047E+00 Seto 2.6496E+00 4090 2,4169E+00 4200 2.2o54E+00 44,0 46.0 2.0134E+00 1.8340E+00 4840 1.6801Ei00 50.0 ttS352E+00 Sato 1,4027E+00 S490 1.28tSE♦00 56.0 1.1716E+00 Sato 1,0715E+00 60.0 62.0 9.80g 1 Ew01 8.9913E•Ol b4so 89254OE■O1 6090 705884E.Ol 6840 6.985bE.o1 70.0 664385E.01 7210 50942ZE•O1 7410 5f4931E■O1 7600 500880E.01 7800 407234E•ot Soso 4f3g55E.o1 62.0 4.100+2E001 6490 3.8340E.01 8600 3.5938E•Ol 88lo 3.3773E•01 90.0 3.1830Em01 A = 0.55 um 0 pA0 92.0 3.009ZE•Ol 9400 218540e.ot 9690 Zg7148E.01 9890 295893E.Of 10040 2,4762E.Ot 102.0 2,3746E•ot 10400 2.2840E•O1 10600 2.ZO39E.01 10800 Ze MSE.O l 11090 2.0716E.01 11280 2.0176E•o1 114.0 1,9711E•Ot 11680 1.9326E•01 118.0 119023Emot 120,0 1.8801E•01 12200 1,865fE•01 12400 11856SE.0t 126t0 118527E.Of 128t0 1.85Z7E.01 13000 1.8557E•01 132.0 118617E•O l 13400 108715E•O1 13680 1t8860E•Ot 13d,0 1.9060E•Ol 14000 1.9319Ee01 14200 109635E•O1 14400 1999SEGOI 146.0 2:0384E•O1 148t0 2g0779Ewol !Soto 2.1162E•ol 152.0 2.1520E•01 154,0 2,1845E•O1 15600 2.214iE•01 15890 20201BE901 ib040 2.2b94E•O1 162.0 292992E•O1 16460 293341E•Ol ibbt0 2.3779E•Ot 16800 2.434tE•01 170,0 2,5041E•Ot 17200 2.S855E•01 17440 246707E•OI 176,0 2.7477E•01 178,0 2.8022E•01 180.0 Z.822OE•Ol 169 DG = 0.3 pm 040 8.0648E+00 290 6*0225E+00 410 708988E+00 6,0 7,7027E+00 890 7,4467E+00 logo 701441E+00 1290 6.8079E+00 1490 6.4499E+00 1610 6.0800E+00 1810 5.7068E400 2010 5.3369E+00 2290 4,9754E+00 auto 496263E+00 2690 4;2920E+00 a890 304744E+00 3000 396742E+00 3260 3.3419E+00 3400 3.1274E+00 3690 2.8803E+00 3810 296501E+00 4000 2.4364E+00 4290 2.2385E+00 44,0 2.0560E+00 4600 108880E+00 4860 167338E+00 5090 105926E+00 5200 194634E+o0 5490 1,3451E+00 5b,0 1,2370E+00 Sato 191380E+0U b0,0 190476E+00 b2,0 9*6513E•01 6490 8,8994E-01 6690 8,2155E-01 680 7,5945E-ot 70:0 7,0312E-Oi 7210 6,5198E.o1 7490 600548E-01 7690 5*6309Eo01 60,10 4:8919E.01 6290 4*5722E-01 84,0 4,2829E-01 6690• u,o2!8E.01 6810 3,7859E-01 9000 3,.5726E-01 a = 0.7 um 0200 3.379SE.4t 9460 3.2051E-O 1 9600 3.0484E-01 9A00 2.9085E-01 100.0 2g7843EoOt 10200 2.6743E-01 10490 2,5770E-ol 10600 2.4911EsOl 10860 2,41SIE-01 11090 2.3So1E•01 112.0 292937E-01 11400 2*24b1E-01 11690 2,2066E•Ot 118.0 2.17ASE601 12000 211492E•O1 122,0 2913OOE001 12490 291164E60i 12690 2.1081E•01 121100 2,1053E-01 13090 2.107SE-Ol 13200 29i156E.ot 13400 291287E-01 13600 291468E-0l 13890 291692E•01 14000 281949E-01 14200 -2.2229E•Ot 14400 2.2523E-01 14690 2,2823E-01 14800 2.3125E-01 15090 2.3423EwO1 1S200 2,371bE-01 15400 294005E-01 15690 294293Eo01 15800 294586E-Ot 160.0 294899E-01 16290 2.5231E-Ot 16400 2.5612E•Ol 16600 2.6053E-01 16860 2,6567E-01 17000 27150E-01 17290 2:7771E•Ol 17400 298305E-01 176.0 2,893IE•Ot 17A00 2,9298E-01 18000 224430E:01 170 DG = 0.5 um a = 0.4 um , Q;0 to 106E+01 too 1*6732Et01 490 1,5787E+01 690 1,4559E+01 8.0 1,3241E+01 logo 12O0 1,1945E+01 1,0727E+01 14.0 9,6042E+00 16.0 8,S814E+00 logo 7,6568E+00 2040 6,8245E+oo 2200 6,0769E+00 84g0' 5,4081E+00 2610 4,8123E+00 28,0 4,2610E+00 solo 3,8009E+00 32.0 303785E+00 3400 2.9995E+00 3680 2,6655E+ou 3800 2,3728E+00 4090 2,1189E+00 4290 1,9016E+00 4400 1,7153E+00 4690 i,5S13Etoo 4890 1,4025E+80 solo 10265SE+00 Savo 1, i 394E+00 54,0 140262E♦oo $690 992408Ew01 S8,0 893305Ew01 6090 79S3i9Ew01 02,0 608447Ew01 b4,0 6.2S57E901 b6.0 5:7426Ewo1 68;0 Se2775E*01 7000 408423Ew01 72.0 404371E•O1 7490 400706Ew01 7680 3,7474E*01 78,0 3,4651Ewol 80.0 3,219SE.01 6210 340037Ew01 6490 298084E.01 86,0 296268Ew0i 88:0 2,4600EPOi 90.0 203157Ewol o ao 92*0 :,1981Ewo1 9400 2001SE*Ol 96.0 2.0149Ewp1 98,0 1.9299E*O1 toor0 1.8455E*O1 10200 10766SE*01 10400 1,6997E*01 10690 1.6467E*01 IOA,o 19602bE•O1 110.0 1.5610E*01 112.0 l.5i42E•Ot 114.0 1.4814E•Oi 116.0 1.4542E*O1 118.0 1.4410E•O1 120.0 104419EVOI 122.0 1.4549E*01 124.0 1,4769E*01 126.0 1.504OE•Ol 128.0 1.5297E w01 130.0 1.S494E*01 132,60 1.5634Ew01 130.0 1i5773Ew01 136#0 1P599SEw0! 138.0 1.6369E*01 140.0 1.6947E*01 142.0 1.7739E*O1 14490 1,8707E*01 14680 1'19810E*Ol 148.0 2.10lOEwOI 150.0 2.22SIE901 15200 2.3453E*01 i54�0 2.4513E*01 iS6.0 2.5343E*0i 1SR.O 25907E*01 160100 2:6221E•OS 162*0 2.6337Ew01 164.0 2.6363E*01 166.0 2t6504Ew01 16800 2 0041Ew01 170.0 2.8245E *01 172.0 3.0206EW01 17400 3.2431E*01 176.0 3.5824Ew01 178.0 3.81S4Ew0i 18000 3.9081E*01 171 DG = 0.5 um a = 0.55 um o p a,o o pt Ogg 1g30d9E+01 9200 2g42709*01 a00 1,2926E+0i 94 0 202967E•0! 4g0 1,2486g+01 96,0 201794E.01 boo 1.1856E+01 9R0O 200729E�01 860 1,1121E+01 10000 109711E•01 1000 1200 i,o331E+o1 905278E+00 10290 10400 19843oE•oi 11,8209E•01 1400 807372E+0q 10660 107598E•01 1600 7,9740E+00 10990 10084E•O1 1800 702537E+00 11000 1,b654E•O1 2090 605759E+00 11240 i,6295E•ot 22,0 509447E+00 11400 1g5988E•Ot 2400 5,3607E+00 11600 1,5714E•01 2600 4,8241E+00 11890 1,5ub6E.01 2800 403352E+00 12000 1,5256E:01 3000 3,8930E+00 12290 125109EPOI 5200 304952E+00 12400 105043E•Ot 3400 3,1391E+00 12600 195066E•Ot 3600 2,8215E+00 12A00 105175E•O1 3800 205383E+00 13060 1,5355E•01 4040 2,2849E+00 13290 105581E•Ot 4210 2,0570E+00 13400 1,5819E•O1 4400 108518E+00 13660 166046E•Ot 4600 1,6669E+00 138.0 10b256E•01 4890 105Q03E+00 14090 1,6465E■oi Soto 1,3505E+00 14200 1,6702E•01 Sago 102172E+00 14400 i,6996E•O1 54g0 1,t001E+00 146,0 1g7373E•01 5000 9,9841E.o1 14800 1,7840E•01 Soto 900482E•01 15000 1,8382E.0t 6060 893159E.01 15200 108969E.01 62g0 7,6105E.01 154gO 199554E•01 6400 6,9649E.01 15600 2,0080E.01 b600 6,3719Ew01 15A00 2g0541E•01 68g0 508301E•01 16000 20917E•Ot logo 5,3385E*01 16200 2t1255E•ol 7200 488963EW01 164g0 211627E•01 7400 405034E•Oi 16690 2,2137E•01 7600 4g1591E•01 16800 292894E•01 7890 3,8590E.o1 17000 2,3473E*0t Soto 3,5940E•o1 17200 2,5363E•o1 8200 303537E.01 17400 2g6937E.01 8490 8600 301315Eeb1 2g9265E•o1 17600 17860 208453E.Oi 2,9585E•0t 8800 207404E•01 160,0 3,0013E•Ot 90,0 205740E•01 172 DG=0.5um a = 0.7 um 0 p(a•0) 000 101202E+01 2g0 1,1049E+01 440 140811E+01 660 1,0381Et01 $to 4.8557E+00 1060 902733E+00 1240 806621E+oo 14�0 800426E+00 16,0 74294E+00 11190 6:81tif♦110 AID to b,;} iuctnu o1,0 5,7212E+0u 1q:0 S.0134E+nu 019 0 N ?11110P #n(I 011 it it: so) I or 4 nil I00 1,14'0411.+0u !!,0 ZistfS7ttou 3410 3.1847E+00 3600 2.8779E+00 3890 296018E+00 4040 243546E+00 4260 2*1336E+00 4420 1,9357E+00 4690 1,7574E+00 4810 1.5960E+00 Soso 1,4492E+00 S2,o 1,3159E+00 5440 1,1952E+00 5680 190862E+00 Salo 908812E•01 bolo 9,0019E-01 6280 a�2163Ew01 6440 75155Ewdl 6690 6�888bEw01 680 6w3245Ew01 70:0 S,81;5E001 7210 S93496Ew01 7490 469298E-01 7610 445522EwOl 7810 4�2145E001 80,0 3.9136E-01 62,0 3.640bEw01 8410 3�402bEwOl 86l0 3.1843E-01 Soso 2,09884Ew01 90*0 2,8158EwO1 0 pa0 42,0 216627E•Ot 9400 2,S280Eoot 9660 20068E.01 4A,0 2,296OEw0t 10000 291947E•Ot 10200 2p1037E.01 10400 2,023SE•01 106*0 159531E901 10A.0 lo0904E*01 11e,n i9A339E•01 112.0 1,7633E-0t 11400 1,7400E001 116on 1,7n54Ew01 1101.11 t �►n ��t 1.b797r•n1 1 .a�.✓�1•.0 I ltu,0 1,6,tU%E•o1 12640 1,6538E w01 12800 1,6610Ewoi 13090 1 i670tE•Ot 132,0 1,68OOEw41 13460 1,6912E-0i 13640 1,7059Ew01 13860 10264EwOt 14000 1,7542E•Ot 142oA 1,7895E•01 144.0 1,8311E-01 14600 1,8779E•Ot 14860 109284E•Ot 15040 16980$Ew01 152,0 20322E-0 t 15400 2,o789E•0t 15600 2,1180E-01 158�0 2,1442E-01 t60:0 2,1749E-01 16200 201999E•01 164.0 2,2301E-0t 16640 2,272aEw01 16840 2,3339EwOt 170,0 2,4207E•Ot t72.0 205332EPOI 17400 2,6625E-01 17600 2,7879E-01 17840 2,8813E-0t 18000 2,9l62Ew01 173 DG=1.0I'm a = 0.4 um p X'� 080 3 205E+01. 9200 1 9S18E•01 3'4113E+01 9400 119146E•Ol 490 b�0 208447E+01 2f3027E+01 96*0 9810 1.8733E•Ol 117999E•OI 810 1,8552E+01 100*0 11b978E•ot logo 1,5086E+01 102*0 1,5977E•01 12.0 192456E+01 !04*0 1g53b0E•Ol 14�0 190416E+01- 10690 1,5159E•ol 1610 897882E+00 loe,o 1.5093E•01 1810 714851E+00 110*0 184805E•01 200 b,4288E+00 11200 1.4231E•01 22:0 515419E+00 11490 1/3635E•01 2490 497979E+00 !lb*0 193327E •O1 2690 491993E+00 118,10 1.3347E+01 2800 S.,1081E+00 120*0 1.3591E•0t 1090 3,2660E+00 12200 1939SOE•01 3200 2,8612E+00 124*0 1,4431E•01 3410 285124E+00 12690 1,5042Eo01 36m0 2a bE+00 12800 1,5607E•01 3810 1,9634E+00 13000 1,5912EP01 4060 1,7391E+00 13290 1.5923E•01 4210 115705E+00 134*0 185853E•01 4460 114500E+00 136*0 195959E.01 4610 113443E+00 13800 1.6424E901 4890 112268E+00 14o*0 18737SE•Ot Solo 181004E+00 142*0 1g8850E•O1 5210 9,8318E•01 144*0 280651E•01 5410 8/8292En01 146*0 282781E•Ol S68o 7/9o17EnOl 14810 285428E.01 Sato 701528E•01 150*0 288571E•O1 6000 604210EmOt 1S290 382061E•Ol 6290 518359E•01 154*0 3*549bE.01 04,0 5/4073E•Ol 156,00 398431E•0! 6610 5109o7EP01 158,0 4g0679Esol 6810 4:7807Ewol 160*0 4.2248E •O1 7010 414058EmO1 162*0 493079E•0l 7200 319912E•Ol 16490 48314OE•01 7490 316252E.01 16bso 492702E.0t 7610 363251Ess41 lbseo 402428E.O1 7810 3,0725E••01 170*0 4a312-tE.01 8010 Z1873ZE•01 17290 4g5529E•01 8200 28716SE901 174*0 560015E.01 8490 215b57E•01 17600 S,6003E•01 86,0 283863E.01 178*0 6,1772E901 8810 29t891E•01 180*0 6g45S H wol 9010 290319E•OI 174 DG = 1 . 0 um a = 0.55 um 0 P(= o P(a'�) 0.0 a,0 2,4235E#oi 2.3146E+01 940 2.06 01 440 201 9600 ,8628E.ot ago 8g0 108208E+0i 1,5786E+01 9800 100 1,7669E•01 logo 1,3636E+01 100.0 1o6786E•Ol 12,0 1400 1:1779E+01 1,0203E+01 10200 10400 1@6063E•Ot 1,5509E•Of 1600 1800 8.8673E+00 7.,7290E+0o 10600 148t0 1,S06fE•Of 1,4b93E•Ot 2090 2210 6.7585E+00 5,9240E+00 110.0 112.0 fo4417E•Ot 194233E•Ol 2400 2690 5,1935E+00 4,5507E+0o 1140 116:0 1.4092E•O1 1,3922E901 28,0 3040 319946E+00 3,St83E+00 11890 120.0 1,3674E•Of 1,340tE•ot 3210 3,1068E+04 12200 12u.o 193226E•0t i,3214E•Of 3490 =6,0 2,7513E+00 2,4504E+00 126�o i,3368E.ot 3800 2.,1951E+00 128�0 130.0 l,370lE•01 1,4218E•Of 40,0 �2,0 1,9696E+00 i,7631Et00 i32.0 1,4846E•Of 44,0 1,5765E+40 134�0 136,0 i�54U5E•01 i,S912E•O1 4690 48,0 1,4104E+00 1,2595E+40 136�0 i,6260E•0! 50,0 f,1198Ei00 140�0 142,0 1�6589E•O1 1,6988E•01 52,0 5490 9.93d9E•01 e0e9epE•o1 144�0 1,7573E•p1 56,0 e.o94uE�o1 146�0 148.0 t,84b4E•01 199687E.01 58 p s0,0 7 4742E•01 6,953QE •O1 15.0,0 2,l183E•0i b2 0 6 4;89E •01 152�0 i54.0 2,287BE.Ot 2,4649Ew01 b4,0 66 0 5,9033E�•01 5 378eE•o1 156�4 158.0 2,6267E•Ot 2,7614E901 689p 7pl0 y*8982E.01 4#4628E•O1 160.4 162.0 208677E.01 2,4473E•01 720 ,,0673E•01 14,0 4 3,7175E•0! 164,0 ibb.0 3,0065E•0! 3,0683E•0! 7610 T8,0 3.4301E�O1 3.2f23E•Ol 1b8�0 170 3.f7l8E•Ot 3,3542E•Ot 80 0 82;p 3 A4t0E•O1 2;e69bE.o1 .0 172.0 174�0 3,3o8E•ot 399732E•Of 8410 860p 2,6833E•01 2,50lOEW01 176.0 l78,0 4�33�2E•01 4,6321E•01 88,0 90,0 203343E•0'i 201865E•0! 180•0 4,76Z4E.0! 175 DG = 1 .0 um a = 0.7 µm o PP(= 0 080 ago ^PP(= 1.9198E+01 1,8651E+01 92.0 9440 2,l356E.0! 2sOSUIEwol 480 640 1:7338E+o1 1,5727E+0! 9600 98.0 1097U7Ew0! 118897EW01 890 104086Ef01 100.0 l,8033E•o1 logo 12g0 1,254iE+01 1,1137E♦01 102.0 10400 1,7274Ew01 1.b7U8EwOl 1400 9,87bbE+00 10600 1,6294E+01 16g0 18g0 8 7478E+oo 7,7425E+00 JOR 0 110,0 lm5902EwOl 104SOEw01 20,o 6,8525E+oo 11200 104965E•o! 22gO 6,0661E+00 11440 1,4549E■O1 24,0 2b�0 5,3728E+o0 407626E+00 11600 1.4286E•Oi 28,0 4,2212E+00 l20,0 1,4203E+01 3090 3,7355E+00 12200 104321E•ol 3260 3.5004E+00 t2400 194548Ew01 3400 2,91b8E+00 12b.0 1g4878E.0! 360 25837E+00 12RG0 1,5254Ew01 38:0 2g2963E+00 130.0 1,5583E+01 4080 2,0502E+0U 13290 195804EwOt 4290 188421E+00 130*0 1,5952E+01 4490 1,06640E♦00 13600 1,6128Ew01 4610 l,505bE+00 13800 10645REwOt 4840 103540E+00 14040 t47023E•ot solo 1,2224E+00 14200 1,7822Ew01 Salo 1.0982E+00 14460 118804Ew01 5480 9:A769Ew01 146*0 199950ES01 5680 898944Ew01 14600 2g1274EwOt Sego a017bEw01 15000 2075REw01 60gO 7:2439Ew01 15200 2g4328E•O1 6290 6,5781E+01 15460 295818Ewot 64s0 600167Ew01 15600 207048E.01 6bg0 5,5381E-01 15840 2,7930Ew01 68,0 5,1072Enol 160,0 2,8452E-01 logo 496956E+01 16240 2,8602E+01 72,0 4,3004Ewol 16400 298696E-01 7Ug0 3,9377E-01 166*0 2,872REwoi 7690 396171Ew0l 16890 299067EwOt 7880 3,3418E-01 17040 3,0172E-0t 8090 3,1103E-01 17200 3,2426Ew01 8200 2,9089E+01 174,90 3g5778E•0! 9.p1 i760n 309630E+0i 8680- • asso 25385E • 1 17880 180.0 4g2QO6Ew01 4,4254E.01 9000 2,2367E.p1 176 DG = 2.0 um a=0.4um 0 P x Ie) 0;0 102297E♦02 2g0 9004069#01 490 506397E♦01 610 305b83Efoi e,o 2031379+01 1090 1.5843E+01 1290 1.1765E♦01 1400 901684E♦00 1640 702031E♦00 18lo 5*8805E♦o0 20to 5.0181E♦oo 2RO0 4.2417E♦00 i4t0 3:S217E♦00 2600 30-1323e♦00 2800 2,9327Ef00 300 2.6408E♦oo 32:0 2.2583E♦00 1400 109863E♦o0 1660 1.6312E400 1690 196b2SE#00 4060 14057E000 4igo 158IIE400 4490 1.a6u4E•00 4600 102519E♦00 4840 1.143SE♦00 Solo 4,76Wwo1 %2.0 699096E.01 S490 707963E.01 9690 7.3736E•o1 solo 61069329*01 600 S.81S9E.01 62:0 Sg1S37E.01 6490 ol :7532E m01 66 4 6800 006708E.01 7090 4g3169E.01 72,0 3�708SEW01 74.0 3.3237E.01 7690 3.0714e.o1 7800 a 7878E.o1 solo 2.6212E•01 8280 245514E.01 840 86:0 a 4739E•01 2:2709E.01 Selo 1,9407E•Oj 90.0 1.07104E•01 0 P(a,e) 192.0 1,7022E.01 94.0 1;7S07E•01 96,0 197484E•01 9A:0 116581E•0! 10090 10496SE001 102.0 19344SE.01 10460 102977E.01 10600 103477E.01 10890 104077E•01 110.0 103724EVOI 11200 1995SSE•OI 114.0 191416E•DI 116.0 1.i111E•O1 11690 121353E•01 12000 1.1792E•01 122.0 11906E.01 124.0 1:2031EVOI 126.0 1 9 2S67E.01 124.0 1.1301E.01 13000 1.3644E.Ot 132.0 10293E.01 11400 1926"E.Ot 13do0 1.276JE.01 13ASO 1@3219E•0t 14000 1.429sevol 14260 1v6307E.01 14400 168212E•Ot 14600 2.0175!•Ot 14490 2.361SE•O1 150.0 2,e372E•01 I S2.0 3, 4637E.0 i 15490 491651E.Ot IS600 4,8343E•01 15860 5@4464E.01 160.0 e.0069E•O1 162,0 0s4171E•01 10400 6�6431Ewot 166,0 6.6373E•0I 16900 6e5967E•01 17000 6.5348E•Ot 172.0 b,626OE.01 17400 619356E•01 176�0 7,414RE901 178:0 799484E•Ot 180.0 8.4408E901 177 DG = 2.0 um a = 0.55 pm 0 P(a,O) 0 P( ) coo 687621E+01 92 00 149136E•o1 200 596399E+01 .94.0 1,817SE•01 410 4g0690Et41 9640 1,7148E00i 610 289172E+01 9800 l9S967E•01 8g0 2,1412E+01 10080 184927E•01 logo 1gbobSE+ol 102.0 lo4230E•01 12,10 1.2359E+01 10400 1084bE•01 1400 988339E+00 106.0 1.3435E•01 logo 880182E+00 10800 1g2933E•0i logo b$b20bE+oo 11000 192580E•01 2080 5.6044E+o0 112.0 1,2u72E•Of 22gO 4.8621E+0o 11490 i,2443E•o1 2490 4.2125E+0o 11640 1.2388E•01 2600 38b039E+00 11880 i,2OS2E•O1 2810 3090 381331E+00 287882E♦oo 120,00 122,0 1,1S16E•Ol 1.12OOE.0i 3210 2,4822E+00 12400 lel19AE.01 3490 3690 281839E+00 1.0654E+00 126.0 i2800 1,1315E•01 1.1670Eo01 logo 40go 1.0186E+00 186826E+00 13000 13200 1,2490E•01 1,36S1E•O1 42g0 4400 1..5013E+00 193322E+00 • 1360 1mSE.41 1,5063E 01 90 466,0 182131E+00 1.1073E+00 i38.0 1152b7E•01 50.0 5280 998480E•01 88436eE•ol 140,0 142.0 1g5578E•O! i.5959E.0i 54g0 5680 7.4411E•O1 6,9pb0E•O1 144.d 146.0 1�676tE•O1 1.84i3E•01 5890 69627bE.01 148�0 15090 2g0772E•0! 2836S2E•oi b0,0 6280 685327E•01 6,178BE.01 152.0 2.7321E•O1 64,0 66g0 5,5483EoO1 489251Ew01 154.0 156�0 3.172SE•O1 385580E•01 o890 40SO52E•01 158.0 3i9039E•0i 7000 7210 491562E.01 307931E•01 160.0 162.0 4,2586E•01 4,6030E.01 7490 384123E*O1 164*0 488391E.01 7610 3,09SiEmot 166:0 49976SE.41 7880 2#9285E.ol 16800 591283E•O1 solo 8240 288928E.01 2.7623E•01 170.0 1720 5838OIE.o1 587908EwOl 84.0 11690 2,5372E.01 2.357OE.p1 174:0 176*0 601972E.ol 6gS144E*ol 8890 .0 292013ES01 2.0316E*O1 178.0 180.0 6,7966E.01 7g039SE•Of 178 DG = 2.0 um C P(A,G) coo 4,S647Etol 2*0 4,0621E+01 480 3*2228Etol 680 2,5005E+01 880 189507E+O1 logo 1,5472E+01 1260 1,2536E+01 14,0 1,0334E+01 1600 885974E+00 t8,0 7*2296E+00 2080 6,1b38E+00 2290 583024E+00 1410 405942E+oo 2680 4,0348E+oo 2800 3,5710E+00 3080 3,1378E+00 3280 287278E+00 3460 2,3841E+00 36.0 2,1104E+00 3880 108789E+00 4080 186754E+00 4200 185240E+00 4480 1,4141E+00 4680 183128E+00 Oslo 1,1939E+00 S0,0 1,0590E+00 52,0 9:4174E•Ol 5400 8,5224E.01 5660 7,7446E•Ol $860 6*9755E•01 bolo 6,2344E•01 62,00 586372E•Ol 6460 502230E•01 660 4,9648E•01 68:0 4:7247EwOl 7040 4*35g4E.Ol 72410 389121E•01 7460 385383E•01 7600 3*2291E•01 7880 2*9782E.O1 8010 2g8195E•0l 82.0 2g6897E•Ol 8410 2,5342EoDl $boo 2*325SEs01 8880 281110E•01 900 189799E.01 a = 0.7 un 0 P(X,G) 270 184512E*ol 9 • 1.93btE•0t 96:0 980 1,8789Eo01 187863E:Ot 10080 186747E•01 102,0 1,5755E•01 10400 185435E.01 106�0 1,5562E•01 108 0 18S473E•01 11000 1g4926E•Ot 11290 104125E.ot 114.0 1,3480E.01 t1660 193203EVOI 11800 113203Ew02 120,0 113293E•01 122.0 193475E•0t 12400 183902E•01 12600 1,4513E,got 128,0 105237E901 13090 t9S851E001 13290 1.604IE•Ot 134,0 1,S9QOE901 13660 185924E•01 13890 1.6146E•Ot 14090 1:7017E•01 14200 118S1;E•Ol 14490 280244E•01 146.0 202249E•Ot 14800 2g4791E•01 t5neo 2,7898E601 15200 3,174JE•0t t54*0 3,S993E•O1 15660 4 0126E•01 158,0 483886E*01 160g0 466656E.01 16260 487993£S01 16400 44853tE•ot 16600 4g7450E•Ot 16Ag0 446447Ew01 17690 4g6328E.01 172,0 419794E.01 17410_ 5,5906EeOl 176�0 6,3299E•O1 17A,A 7,1435E•O1 18000 7,5961EP01 179 DG = 5.0 um x-0.4pm p(a,O) 0 p"= 0 a o 70956SE+02 9200 IsPOSE•ol 2,0 2,6889E+02 94.0 1,t259E•01 480 8.4314E+01 9b0 1,120SE•01 690 3.437bE+01 98:0 9,7706E.02 8 0 1 8114E+01 100*0 9,8068E-02 logo 1,0982E+01 102*0 996403E •02 1290 6,8298E+00 10480 9,2371E:02 1490 504713E+00 106.0 8;7764E.02 16,0 5,1956E+00 108.0 7,3019E •O2 18,0 4,0134E+00 110.0 6,993SE •O2 2090 3.1310E+00 112.0 7,4079E-02 2210 2,9371E+00 114.0 7,449SE•O2 2400 3,2867E+00 116.0 7,3793E-02 26.0 2,4165E+00 118.6 7,6182E-02 3000 1.9894E+00 t2290 6:919SE•02 3200 2,1999E+00 12400 6g77S5E•02 3460 167970E+00 126.0 6,8843E&02 3610 1,4804E+00 128*0 5,2239E.02 3800 1*4041E+00 130*0 4„534OE•O2 4000 1,4186E+00 132*0 S,978OE•02 42,0 1,3284E+00 134.0 7,0037E-02 4440 1,0442E+00 136*0 6j6038Ewo2 46t0 9,6549E•Ol 138*0 7,1004E-02 48t0 8109514Ei01 140*0 8,2036E-02 solo 8.73S8E'ol 142.0 890308Ewo2 52,0 8tS406Ew01 144*O 709962E-02 S4t0 6,8448E•Ot 146.0 1,1021E-01 S680 S99S07E•01 14800 1,2230EoOl S890 60377bE•01 150.0 1*4994E•O1 60t0 62.0 5,S437E•01 5,8233Evv01 152*0 15400 2,1790E-01 3s0461EwOl 6400 403533E.01 15640 3,9510E-01 6610 0800 3t9400E•01 3:7307Ew01 158*0 160*0 5,1616E-01 607709Eo01 7010 3.4408EP01 162*0 79863SE.ol 72t0 7460 3*0768Eool 3t0094Eool 164*0 16600 7,7468E.01. 7,0390E-0t 7600 7800 2.05665E.01 2t7041E.01 168*0 17p�p 7r6104E•01 8,3835E.01 8000 Sato 2t3869E.01 1.9631E.p1 172*0 17400 6.SOOIE•01 9,6368E.01 104,0 $b.0 1,6655E-01 1,8343E-01 17600 178*p 1,1466E♦00 1,0917E+00 8880 9090 1064S1E.01 1t4554E«ol 180*0 9,9826E-01 :N DG = 5.0 um a = 0.55 pm o P ale Olo 4,1757E+02 2,0 2,0231E+02 4,o 8,2805E+ol 600 3,7331E+01 $to 2,0382E+01 10.0 1.3639E+01 12.0 9.5098E+ou 1410 6,3674E+00 1600 541845E+0o 1890 498925E+00 2010 4.0161E+00 2210 3,1430E+00 2400 2,9589E+00 266q 2,9736E+00 2800 2,4711E+0o 3090 2,0062E+00 32,0 1:8844E+00 3400 148918E+00 3600 107191E+00 3890 1,39SSE+00 4040 1,3041E+00 4290 1,2193E+00 4460 1,2382E+00 4610 1,0343E+00 4800 866689Ew01 Soso 842807EeOl 5200 8,1049E•O1 5400 892681E•O1 $690 609598Ew41 58,o 5,5694Ew01 600 5IRS088Ew01 62:0 5r3200Ew01 6440 5,0124Ewol 66,0 406319Ew01 Oslo 306985Ew01 7060 3,0699Ew01 72110 3�4453Ew01 7460 3,5201EwOl 7690 302578Ew01 760 solo 206041Ew01 6240 242883Ew01 8400 109175E•Ol 86,0 109043EN01 8810. 107620EwOt 90.0 198360Ew01 181 6 P J1,0 9260 19624OEool 9400 1s3971Ew0i 96.0 1.2113Ew01 98.0 100863Ew01 100.0 1.0096Ew01 102.0 1.0004Ew0i 104.0 10204Ew01 106.0 9.0620Ee02 10800 8,2523Ew02 11000 8s2967Ew02 11200 8s6000Ew02 11400 81045AEw02 116.0 1.1856E902 11880 79581bEw02 120.0 7.5982Ew02 122.0 a 0725EwO2 12400 7.5396Ew02. 126*0 6.7658Ewo2 128.0 7.i720Ew02 130.0 708774Ew02 132.0 7.7014Ew02 134.0 607032Ew02 13690 6.5703Ew02 13800 8,1393Ew02 14000 9.4488Ew02 142.0 9.7912Ew02 14490 1.2569Ew01 146.0 1.5335Ew01 14890 1.7296Ew01 150,0 2.010sEw01 152.0 23190Ew01 154:0 2:8534Ew01 15660 39974OEoOl 15860 418310Ew01 160.0 5.8b29Ew01 16290 6.5817Ew01 16400 7.1868Ew01 16600 7.1876EW 168.0 7.3058Ew01 1700 a 2375Ew01 172:0 9:712AE901 174.0 1.0614E+00 1760 1.Ob10E+00 178:0 8.9788Ew01 18090 8.3257Ew01 DG = 5.0 um a_0.7um 1 P �`�°) 0 P(a.6) 090 2,6480E+02 920,0 1875.e0 wE 01 ago 1,5749E+oa 9400 1,6683Ew01 ago 7,7035E+01 96.0 1,5698E901 610 4,0296E+01 9800 1g406SEw01 ego 2,3568E+01 10000 194109Ew01 1090 1,4828E+01 10200 115139Ew01 1210 9,8602E+00 10400 104722ED01 140. 7,5809E+00 106,0 1g3075Ewol 16:0 6,3b76E+00 108,0 1g1202Ew01 logo 5,0234E+Oo 11090 1g0241Ew01 20;0 3,9793E+o0 11200 1,0893Ew01 2200 3,S115E+00 11400 1.2510Ew01 24g0 3,3596E+Ou 11600 1,3644Ew01 26g0 2,8113E+00 11890 192553Ew01 28,0 2,30o1E+oo 12000 i,oS33EwOl 3000 2,1436E+00 12200 902263E%02 3260 2,1586E+00 12400 9g1035ewO2 3410 1.4176E+00 12600 6 0195EwO2 3660 1,6658E+00 12800 8,3564E■02 3890 1,5810E+00 130,0 8g6422EwO2 4010 185058E+00 132,0 91S672EwO2 4290 1,3993E+00 13460 1g0699Ew01 44g0 1.1188E+00 13600 1,1237EwOt 46g0 967098Ew01 138,0 1,2433Ew01 4810 9s2299Ew01 14060 1g3612Ew01 5000 9,4042Ew01 14290 1i3832Ew01 Sago 8g9965Ewo1 14400 19460SE901 S410 7,3557Ew01 14600 196626Ew01 56g0 6,6473Ew01 14880 1195SbEwOl SO10 604689Ew01 15080 2,3148E901 60*go 604426Ew01 152,0 2g7975Ew01 6290 6,6536E901 15400 3,S5b4Ew01 6490 5,5700Ewol 15640 40107EsOl bbg0 496199Ew01 15800 5,1053Ew01 e8,o 400291Ew01 16020 •6 0 903Ew01 7060 306564Ew01 16290 7,5079E.01 72g0 3,5903EwO1 16460 8g0816Ew01 74g0 3,6784Ew01 16600 8g9124Ew01 7600 3,6199E901 16800 994776Ew01 7890 3,3127Ew01 17000 a 8497Ew01 8090 2,7367E•o1 17290 8,2381EwOt $200 2,2102Ew01 17400 800021Ew01 84g0 2*1747Ew01 17690 9,1128Ew01 86,0 2,2305Ewo1 17A90 1,0573E+00 tl890 2gMbEvOl 18000 1,i98fE400 9000 2,05S4Ew01 182 DG = 6.0 ufn a=0.4um 0 P(a,0) 0.0 161126E#OJ 2.0 2.8064E+02 4.0 7:9413E+01 640 3.4158E+01 ego 1.6399E+41 10.0 8.3863E+00 12.0 6.2203E+00 14.0 6.4324E+00 1690 4.4826E+00 logo 3:4664E+00 2000 3.3067E+00 22.0 3.6043E+00 2490 2.7225E+00 26.0 2*SZ49E+00 28�0 2.3341E+00 30.0 2•SBSSE♦00 3200 1.8914E*00 34.0 1.7029E+00 36.0 1.5552E+00 38.0 1.7358E+00 40.0 1.3523E+00 42.0 101528E+00 44.0 1.1949E+00 4610 1.0661E+00 48.0 1*1049E+00 Solo 8 • t 922E.0 l Salo 7,0991EwOl S4.0 70297OE•O1 S6.0 640113E-0l Salo 6.1991EoOl 60.0 5,1920E•O 1 62.0 64.03 4.1039EoO1 4.0253E.O l 66.0 4�2403E.01 68•o 3.2681Evot 7010 31101E-01 7200 2:93SIE901 74.0 267378E.O1 7o•0 2.1644E.O1 78.0 22893E-01 80.0 2:0834EM01 82.0 1.8139EwOl 84•0 2�0606EwO1 86.0 1.7027E•Ol 48.0 90.0 1*3813E•O1 1.4674E-01 0 P(A,p 9200 1.2963E.01 9480 l•1839E•Ot Q6.0 1.2426E-0S 98.0 1.0064E.01 100.0 9.5558E.02 io2s0 $gS544E•O2 10400 798424EW02 106D0 7.9941E.02 10800 7.461BE.02 110.0 6.6036E-02 11200 6.1884E-02 114.0 6.387SEO02 116:0 S.6316E•02 118.0 6.228tE•O2 120.0 5,8581E-02 122.0 3.8323E.02 12400 4.3659E*02 126.0 6.i722E•02 12800 6.1479E-02 130.0 5.5222E-02 13290 4.1597E002 13490 5.3466EP02 13600 6.2306E.02 138.0 5.5411EP02 14000 613714EV02 142.0 8.0479E-02 144.0 $.5606E.02 14600 9.7589E.02 14800 1.2500EwOt t50.0 1.3792EwOt 152.0 19783uEo01 154.0 2.6000EwOt 156.0 3,4989E.01 158.0 5.1256E-01 160.0 6.3263E.o1 162.0 7.4068E-01 1p40 718683E-ol 16600 7.7357E-01 168.0 7.3928E.ot 170.0 7.9157E•Ot 172.0 8.6179E•Oi 174.0 1.0965E404 17600 1.3260E+00 17800 t•2t44E+00 1B0.0 8.7101E•Ot 183 DG = 6.0 um x = 0.55 um 0 P(X,fl) 4. 0,0 5448 o2 9200 lg5174Ewo! 29O 2,3864E+02 9490 1t2810E•0t 4,0 8,4333E+01 96.0 1.1275Ew01 690 3,6464E+01 98.0 1t02511E•0l ago 1.9548E+01 100,0 110532Ew01 logo lot672E+01 10290 987556E•02 12,0 73Si1E+00 10490 a 7953Ew02 1490 S:6980E+oo 10690 9:860SE002 1680 5,3109E+o0 10890 899522Ew02 1840 11,1334E+00 11060 895131E902 2000 3,3929E+oo 11200 768283Ew02 2240 3,20.12E+00 114*0 608689Ew02 2400 342902E+00 11690 798401Em02 2b90 2,5045E+00 118.0 890501E•02 auto 2,1333E+00 12090 T'3009E•O2 3010 2,0002E+oo 12290 7go228Ewo2 3290 2,1568E+00 12490 699672E.02 3400 1,7476E+00 12690 6g9512E*02 3690 1.4438E+00 , 128,0 590821E•O2 3890 1,3488E+00 13000 592856ES02 4090 194409E+00 13290 7t8909E•02 4210 1,3234E+00 13490 895595Ew02 4400 190819E+00 13690 7g4026Ew02 46,0 996575E•OI 13840 797631EwO2 4840 Solo 8,6523E+01 899038Ewol 140.0 14290 804944E.02 707718E.02 Salo 5410 8*4115E.O1 698993EwOl 14490 7.812lEwO2 5690 S99678E.01 14690 14890 1t1487Er01 1,3686E.Ot $860 60.90 690795Ew01 5,8605EwOl 15090 152.0 1,1801EwOt 2,2154EwOl ba10- 6490 598777E.01 4,6363E.O1 15400 15690 298313EwOt 30779SE901 6690 0840 4,02?bE.Q1 3,7i29E.01 15840 5,6QO4EwOt 7090 394780E.01 1609n 162,0 792422E.01 703746E•01 7240 7490 3,3912E.01 3040t8E.o1 164.0 795574EwOt 7690 ?,58Z3Ewol 16600 168,0 T 20STEw01 7,8312Ewol 7860 8000 297114E*ol 2,5480Emot 17090 90357EwOi 8290 202744Ewol 172,0 174,0 9g217bEwOl 99i178E•0l 8410 8600 118408E'01 14851bE.O1 176 0 9 9483E.01 8890 197S51Ewp1 l78,0 18090 1,1056E+QO 1g1667Et00 9060 1t6071E•01 184 DG=6.0um 000 s,S921E♦02 290 1.8132E+02 490 7:9809E+01 boo 400735E+ol Sao 292247E+01 i0:0 1z,o 8:8730E+00 1490 782267E+00 1610 563723E+00 1800 4,1778E+00 2010 3.7811E+00 220 3,6245E+00 24:0 299210E+00 260 2.5204E+00 28:0 204463E+00 30.0 2,4644E+00 32,0 t,9SO9E+00 3400 166958Et00 3bIo 1.6065E+00 3800 106441E+00 4010 1.4773E+00 4200 1*2424E+00 4490 191644E+00 4600 t,ttloE+oo 4800 1,0606E+00 Solo 898863Ew01 silo 707652Ew01 $460 78510bEw01 bbl0 bf5813Ew01 sago 6�5287Ew01 6000 5:5942Ew01 62,00 4OS480Ew01 6490 4.b734EwOl 6640 4661t7Ew01 6880 400085Ew01 70.0 3,7656Ew01 720 3:6795EwOt 74:0 3.0608EwOl 7600 204464Ew01 7890 2.5892EwO1 8060 29386 EwOl 8200 2*4390EmOl $400 2OS61ZE•Ol 8640 2�2227Ew01 8tl.0 1.6931E•Ol 9020 1,6677Ew01 a=0.7Un e P(a,e) 9200 i,SB 7E 01 9400 l,S96OEw01 96.0 9800 1,6S82Ewot 1,5529Ewot 10000 t,3948Ew01 102,0 10957Ew01 104:0 100682E.Ot 1060 1,0517Ewot 108:0 190623EwOt 110.0 998925Ewp2 112.0 9t5926Ew02 11480 9,6554Ew02 11600 9,2290Ew02 11a,0 8mSlOOE•o2 1200 718155Ew02 122:0 603083E•02 6.b224EwO2 t2600 7,630aEeo2 128.0 8,3037Ew02 13000 8,2523E•O2 132.0 89965OEw02 13490 9,3877Ew02 13680 949709EwO2 13890 98942tE•O2 140.o 19057BE901 14200 1,1701EwOt 14400 193316Ew01 1IJ690 t,5252E•Ot 148.0 197965E901 150.0 2,0123Ewot 15200 2,3833Ew01 15u.0 3,1284E901 156.0 4,0959E.Ot 15800 5,3554EwOt 160.0 6171b5EwOt 16200 7997HOEw0t 164�0 8,5063Ew01 166:0 896AOOEw01 16840 8,24o6Ewot 170.0 8,3210EwOt 172,0 9,0794Ew0t 174.0 1,o'623E+00 176.0 1,1837E+00 17800 1,1326E+00 18000 1,1702E+00 185 0,0 341416E+03 2.0 3,3446E+02 40 6,0017E+01 6:0 2,0556E+01 &to 1003S4E+01 10,0 72783E+00 1200 4+9905E+00 1460 4,4552E♦00 160C 4,6422E+0tt 18.e 3,3900E+00 2090 2.4238E+00 22,0 2,5360E+0o 24.0 3i32t8E+00 2600 2+5297E+00 28.0 2,1617E+00 30.0 1.8642E+OQ 32.0 2,2933E+00 34.0 1.7068E+00 36.0 1,4710E+00 3890 1.4628E+00 40.0 1.2687E+00 42.0 1.3003E+00 44.0 1,0522E+00 460 964500EmOl 48:0 8,6352E-01 Soto 7.7440EV-01 5260 804416E.p1 5460 6 9212E-01 5600 5,9936Em01 Salo b,302bE•01 6010 S,0728Em0t 6280 595583E.O1 0410 3,5909E.01 66.0 3,9871Em01 68.o 3,3947e•01 70.0 3,1150EmOl 7,240 2,6914E.O1 7400 Z93358E•01 7610 2,0913E=01 80,10 • 1:7160E.a1 . 1 1 8200 107361E.01. 64,0 1,5345Em01 8600 t,3907Em01 9000 i;I2299E•Ol DG = 10.0 um x = 0.4 pm 9200 8*7944E.02 9400 19020GE•01 9600 8,8620Em02 9690 8,2212E902 10090 7.t107E•O2 10290 668097E.02 10400 6,6945E-02 10690 5,4047E-02 108.0 4085SP1EP02 tt0.0 4,6377E-02 11290 4;5968E•02 114.0 408603E•o2 ttbl0 4l5828Em02 118.0 4,5963Em0i 12000 3.6626Em02 12290 4.S97OE902 124,10 3.9S4tEm02 t2b.0 4.2393E-02 128.0 3.3869E.O2 13090 3.1 16SE o02 13200 3.3250E«02 134l0 4,808tE.02 13690 401103E-02 139*0 3.9p23E•O2 140.0 4.5B45E•O2 14290 4,3432E-02 14400 4,7809E*02 14600 6.t37?E•O? 148.0 6,5630E-02 15890 8,2346E-02 15200 1.2595E-0t 15440 2#2242E.01 t56t0 3,442tE•O1 15A/0 S,1bblEm01 16090 7,b849E•01 162.0 8,3350E-01 164 * 0 6, b505EP01 166.0 5,7081E-0t 16860 b,2S42Em01 170,0 7,2376E-0t 172,10 7.5246E.Ot 174.0 1.0194E+00 17600 1 , 4827E+00 178,90 1,7329E♦00 180.0 9,1932Em01 0.1 DG = 10.0 um Q 0.0 1.6527E#03 ago 3.2431E+02 4.0 7.8859E+01 6.0 2.4390E+0i ago 1#2268E+ol logo 9,2333E+0o 1Z.0 7,0872E+o0 1'4a0 4.0919E♦00 f6.0 3,9799E♦00 i8a0 4,4184E+00 logo 3.S4S5E+00 Zito 2.7037E+o0 24.0 2.6000E+!o 2690 2.4205E+00 2800 2,3S30E+00 Joao 1.9059E+00 3210 1,8434E♦o0 3400 1.8286E+00 36.0 1*6454E+00 3890 1.3106E+00 40.0 1.3277E+00 42.0 1,1131E+00 44.0 102802Efoo 46.0 96 743SE901 4890 8.2255E•Ol Soso 892317E.01 S2.0 79Sl21E•O1 S400 70730SE.0i S6g0 6.3669E•Ol 5800 591430E•Ol 6010 501914E,01 620 46138Emoi 64:0 4:271Hwoi *b,0 6800 4,3592Ew01 3a2580E.oi 7000 2,6874E.0i 720 74:0 3,1122E901 2,8495E.01 7660 206069ES01 7ago 8090 20971E•Oi 2:187OEool 82.0 1,856bE.ot 84;j 1,5468E.01 8690 1.7003E.O1 $ego 1.2922E.01 9010 103860E•0i a = 0.55um 0 Pad 9290 1.1120E W 94.0 10371E•ot 96.0 9g36i8E.o2 98:0 7,8050E•02 1000 701817E•02 102:0 bo315OE•O2 10400 6s69?7Ew02 10600 587462E.02 10890 S,i555E•O2 11060 5g3868E.02 11200 S.5367E•o2 114*0 5gS315E.02 11600 4,7693E•O2 118.0 4,8507E.02 120.0 4.5075E.02 12200 S o MSEw02 12490 4,2683E.02 12690 3,S343E•O2 12800 4.2719E*02 13090 4,S446Ew02 13290 4,1629E•02 13490 3,SO4OE.o2 13600 3.4405E•02 13800 494392E•O2 14000 -S.5252E•02 14200 4985SOE•O2 144.0 6oSS09E•O2 146�0 7e8l54Ee02 14A:0 9g358SE=02 150,0 1085 %mOl 1520 114233E•01 154:0 2g0208E•01 15690 3g9002E•01 158,0 S 1219E.01 16000 6,8064E•01 16290 699125E.O1 16400 6,7p59E•01 16600 6a4324E.0t 10890 695291EW01 17000 797627E.01 172,10 9.29$9E•Ot 17400 1,1345E+00 1760,0 1.3415E+00 17800 1.1624E+0O 180,10 6g0788E•01 187 OG = 10.0 um A = 0 P(X,0) 0�0 1,0363E+03 2:0 2,9556E+02 410 8,4219E+01 boo 3,0616E+01 860 1 5879E+01 lo,o 1,0547E+01 1220 602757E+0.0 14.0 160 5,1969E+00 5,1354E+00 18:0 490094E+00 2090 3,0535E+00 22s0 2,8477E+00 2490. 391410E+00 2610 2,5329E+00 2890 2,0336E+00 3090 1,9797E+00 3290 2,2379E+00 3400 1.09207E+00 3690 1,9092E+00 3890 1*5033E+00 4080 1,4204E+00 4260 to4677E+00 4490 1,0822E+00 4600 9,514SEw01 4860 8,9091E-01 Solo 896757EPOI 5260 806788Ewol $400 6,3056E-01 5600 5,7304E-0.1 5800 5,6387E-01 600 5,0441E-01 62:0 5,366OEw01 6490 493073Ew01 6610 3,8706Ew01 6800 3,2562E-01 70,0 3,0359E-01 7290 2,9542Ew01 7480 2,6654E-0i 7600 2,6294EwOi 7890 a 5834E-01 8090 2,1122E-01 8280 195734E-01 8490 1,8043Ew01 6600 1,7165E-01 8800 1,6065E-01 9090 107134Ew01 0.7 um F. 0 P(A10) 9280 192614E.01 9400 102479Ewot 9600 1.1375E-01 9810 9,80S7EwO2 100.0 9,7283EwO2 102,0 1.0176EwOt 10400 994704E-02 1060 8�642TEw02 108:0 7,0802E-02 11000 bs865SEw02 11200 7,6000EwO2 11400 7,692tEwo2 11600 l!,2341EwO2 11890 6,2353EwO2 12000 5,5198E-02 12280 583670EwO2- 12460 S94lS6Ew02 12690 4,7891E-02 128,0 59335tEw02 13000 5,5562EwO2 13200 5.5605E-02 13400 6,9402E-02 136,0 6,3578E-02 13890 6,3616E-02 14080 794934EwO2 142.0 7,9538E-02 14400 883.610E-02 14600 1,0838E■Ot 14ROO 192155EwOt 15000 1.4688Ew01 15200 1�8696Ew01 15490 2.6538E-0t 15600 3,3697E-01 15800 498033EwOt 16000 642154Ewpt 1b2,o %3836E-01 16400 7s66A7EwOt 16600 7,6803E-01 16890 8a0254Ew01 17no0 798523EwOt 17200 8012%wOl 17460 1,0879E+00 176 * 0 1.1791E+00 171400 1,2030E+00 t8090 99916OEwO1 APPENDIX C PLUME DISCOLORATION PARAMETERS FOR VARIOUS NO2 LINE -OF -SIGHT INTEGRALS AND BACKGROUND CONDITIONS This appendix contains the following plume -discoloration parameters: > Blue -red ratio > Plume contrast (a = 0.55 ym) > Plume perceptibility eE (L*a*b*). These parameters were calculated using PLUVUE, the plume visibility model, for a scattering angle of 90%* an assumed horizon -sky viewing background, and the following input conditions: > NO2 line -of -sight integrals from 1 x 102 to 5 x 107 ug/m2. > Plume -observer distances rp, and background visual ranges ry of 5, 10, 20, 50, 100, 150, 200, and 250 km. 0 * For plumes that are predominantly NO2 (e.g., plumes from well - controlled power plants), the values of these parameters do not*vary significantly with scattering angle. 189 .r s%o 0 BA"GROUND VISUAL RANGE (KM) 10.00 PLUME-OBSERVEI1 DISTANCE ( IUD 5.00 (NO2)INTEGP.AL BLUE -RED RATIO CONTRAST DELTA E 1.0E+0)2 1.000 2.0E+02 1.000" 5.OE+02 1.000 1.Oi.+03 1.000 2.@E+@3 1.000 3.OE+03 1.000 I.OE+04 1.000 2.0E+04 .999 5.0E+04 .998 1.0E+05 .996 2.0E+05 .992 3.OE+05 .982 1.0E+06 .971 2.0E+06 .961 5.©E+06 .960 1.0E+07 .970 2.0E+07 .992 5.0E+07 1.049 -.000 .000 -.000 .001 -.COO .002 - . 00r) .004 -.009 .007 -.000 .018 -.000 .037 -.0bs3 .073 -.001 .1a1 -.002 .355 -.005 .684 -.011 1.533 -.021 2.587 - . 040 3.663 -.079 5.761 -.114 7.422 -.136 6.625 -.141 9.727 BACKGROUND VISTTAL RANGE (MM 10.00 PLUP-E-OBSERVER DISTANCE (KM) 19.00 (Nn2)INTEGRAL BLUE -RED RATIO CONTRAST DELTA C (UGAN**2) 1.0E+02 1.000 -.000 .000 2.0E+02 1.000 .000 .000 3 . C`Z+02 1.000 - . 009 .000 1.0C+03 1.000 -.000 .000 2.0E+03 1.0.00 -.000 .001 3.@E+03 1.000 -.004 .091 1.OL+04 1.000 -.000 .003 2.00+04 1.000 -.000 .00S 3.0E+04 1.000 -.000 .013 --' 1.0E+03 1.000 -.000 .026 2.0E+03 1.000 -.001 .030 3.9E+05 .999 -.002 .118 1.0E+06 .999 -.003 .218 2.0E+06 .999 -.006 .387 3.0i+06 1.000 -.011 .776 1.0E+07 1.003 -.016 1.131 2.0E+07 1.009 -.019 1.497 3.0L+07 1.023 -.04.0 1.901 BACIZGROUND VISUAL F.ANCE (KM) 20.00 rLUi-OBZ-7Z,RVE'.1 DISTANCE (KM) 3.00 ( Pin2) I IfTECRAL BLUE- ILED RAT i O CONTRAST DELTA E 1 .02+02 1 .OGO - . 001) ' .001 2.Os+02 1.O00 -.000 .002 5.0u+92 1.000 -.000 .05 1 .0E+()3 1.000 - . 0G3 .01 ! 2.OE"03 1.000 - . 000 .021 5 . ©'u+03 .999 - . 0+.0 .053 1.OE+04 .990 -.001 .105 2. QL+04c .996 - . 001 .209 5.OE+04 .991 -.0013 .517 _+ 1.0E+05 .961 -.006 1.017 to 3.0E+05 .965 -.012 1.9OJ 5 3.OE+05 .922 -.0313 4.437 1.0E+06 .374 -.057 7.531 2.0E+06 .324 -.106 11.153 3.0E+06 .302 - . 21 1 14.719 1. OE+07 .313 - . 304 17.127 2.0E+07 .Uz4 -.362 13.7-23 5.0E-1•O7 .962 - . 376 19.729 BACKGROUND VLSUAI, RAKGE (KM) 20.09 PLUM -OBSERVER DISTANCE (M) 10.00 (V)2) IMTC'Gf'tAL BLUE-MED PATIO CONTR.AGT MLTA E ( UG✓M* :;:2) 1.0C+03 1.000 -.000 .000 3.4E+02 1.000 -.000 .001 3.0E+02 1.000 -.000 .001 1.0E+03 1.000 -.000 .003 3.OE+03 1.000 -.000 .005 5.03+03 1.000 -.000 .013 1.0E+04 1.000 -.000 .026 ' .0%+04 .999 -.009 .951 3.0E+04 .', 9a - . ()91 .126 -• t . 0E+05 .996 - .993 -.005 .477 3.0E+05 .9A4, -.011 1.071 1.0E+06 .974 -.021 1.016 2.OE+06 .965 -.040 2.760 3.00+36 .764 - . ©79 "r . 3i3O 1.0E+07 .975 -.tt4 3.894 3.0E+07 .996 -.136 6.989 5.0E+07 1.054 -.141 7.951 BACMMOUND VISUAL RANGE (KM) 20.09 PLUME-OBSETIVER I► I STANCE ( b 1) 15.00 (K02)INTEGRAL BLUE -RED RATIO CONTRAST DELTA E (UG/M**2) I.OE+62 1.000 -.000 .000 5.0r+e)2 1.000 ' ' - . 000 .0". 1.0C+03 1.000 -.00V .001 :.OE+03 1.000 -.00?3 .001 3.00+03 1.000 -.OEO .003 I.OE+04 1.000 -.000 .007 2.OL+04 1.000 -.000 .013 3.0E+04 1.000 -.000 .032 1 .OZ+.05 .999 -.001 .064 2.0E+03 .999 -.002 '.124 3.0E+03 .997 -.604 .233 1.9E+05 .995 - . 0011 .502 2.OE+06 .994 -.015 .60.15 5.0 +06 .996 -.030 1.601 1.0E+07 1.001 -.043 2.313 2.0+07 1.013 - . 031 ` 2.636 3.0E+07 1.042 -.053 3.473 BACMROUND VISUAL RANCE ( KM 29.00 PLUME-00-SEMER DISTANCE (101) 20.00 (No2) mm,"GRAL BLUE. -RED RATIO CONTR:4ST DELTA E UG/Pl*::'2 ) 1.00+02 1.000 -.000 .000 2.0E+02 1.000 .000 .9E`0 3.0E+11)2 1.000 -.000 .000 1.0E+03 1.000 -.000 .000 2.0E+03 1.000 -.000 .000 5.0E+03 1.000 -.000 .001 1.0r%+04 1.000 -.000 .002 2.0E+04 1.000 -.004 .004 5.0E+04 1.000 -.0N, .010 -+ 1 .0E+05 1.000 -.000 .019 to un 2.OE+05 1.000 -.001 .037 5.Or+os .999 - . 002 .088 1.OZ+05 .999 -.003 .1G6 2.OE+06 .999 -.006 .305 5.0E+05 1.001 -.011 .629 1.0E+07 1.004 -.415 .936 2.0E+07 1.010 -.019 1.217 5.ON+07 1.024 -.020 1.541 BACKGROUND VISUAL RANGE (KM) 50.00 PLIME-OESERVEr, DISTANCE ( K 1) 5.00 ( NO2) INTEGRAL LLi7E-RED iL1TI0 CONTRAST DELTA E I.OE +02 1.000 -.000 .002 2.0I:+02 1.000 -.000 .004 5.0E+02 1.O06 -.000 .010 I.0':•h03 1.000 -.000 .019 2.0E+03 .999 -.000 .0139 3.0E+03 .998 -.001 .096 1.OE+04 .993 -.001 .193 2.0E+04 .991 -.002 .384 3.0E+04 .977 -.006 .933 -+ 1.0E+05 .956 -.011 1.030 uD 2.OE+OS .913 -.023 3,661 3.0E+03 .813 -.053 8.469 1.0E+06 .693 -.103 14.795 2.0E+06 .574 -.190 22.827 3.0G+06 .504 - . 360 29.343 1.0E+07 .516 -.546 32.047 2.Oa.+07 .552 - . 601 33.594 3.9M+07 .669 - . 676 33.707 BACKGROUND VISUAL RANGE (KM) 50.00 PLULM-OWERVEn DISTANCE (KM) 10.00 (NO2) I WrEGRAL BLUE -RED RATIO CONTRAST DELTA E ( UG/M...:2 ) 1.0E+02 1.000 -.003 .001 2.0E+02 1.000 -.000 •002 3.0E+02 1.000 -.000 .005 1.0E+03 1.000 -.000 .011 3.0E+03 1.000 -.000 .021 5.0E+03 .999 -.000 .053 l . 0r.+04 .998 - . 001 .106 2.0E+04 .993 -.002 .212 3.0E+04 .9811 -.004 .524 ...� 1 .0E+05 .977 - . 007 1.032 to 2.0E+05 .956 -.015 1.996 S.OE+03 .904 -.026 4.324 1.0E+06 .B44 -.069 7.718 2.0E+06 .783 -.128 11.499 3.0E+06 .754 -.257 13.267 1.0E+07 .771 -.369 17.968 2.0E+07 .811 -.440 19.(rto 3.0E+07 .932 -.437 20.912 BACKGROUND VISUAL RANGE (KM) 50.00 PLUME-OESF,MT-It DISTANCE (ID'I) 15.00 (NO2)INTEGRAL BLUE -RED RATIO CONTRAST DELTA E (UG/M**2) 1.0E+02 1.000 -.000 .001 ...0E+n2 1.000 -.000 .001 3.0E+0 1.000 -.000 .003 1.0::+03 1.000 -.000 .006 W.OE+03 1.000 -.00U .012 3.0E+03 .999 -.000 .029 1.0E+04 .999 -.001 .059 2.0E+04 .998 -.001 .117 3.0E+04 .994 -.003 .239 1.0E+03 .988 -.005 .566 to 00 2.0ET08 .978 -.010 1:095 3.9E+05 .951 -.024 2.462. 1.0E+06 .921 -.047 4.162 2.0E+06 .690 -.087 6.196 5.0E+06 .3Z0 -.174 8.C69 1.0E+07 .396 -.250 11.295 2.00+07 .931 -.298 12.971 5.0 +07 1.002 -.309 14.111 tiA-Rt./LOtMD vTsvaL nAttcE cWWl PLU"f;-OV-SERVI.r, D rsTAM7F f Y"I) 20.00 ( P 02") i MTECRAL IJL';E-nr.i) RATIO CONTPUST DELTA E 1 .0"1 +^2 1.000 - . 0GO .0Oo 2.OE+02 1.000 -.0011) .001 5.02, + l2 1.000 -.001) .002 1.0E+03 1.000 -.090 .003 2.0E+03 1.000 -.000 .007 3.0E+03 1.000 -.000 .016 1.0E+04 .999 -.000 .033 2.0 +04 .999 -.001 .065 5.0E+04 .997 -.002 .160 --A 1.0E+05 .994 -.003 .314 �o 2.0E+03 .909 -.007 .606 5.OE+03 .975 -.017 1.361 1.OE+06 .960 -.032 2.300 2.0E+06 .945 -.059 3.515 S . 0E+06 .943 - . 1 17 5.343 1.0E+07 .957 - . 169 7.404 2.0E+07 .985 -.201 8.01,13 5.0E+07 1.064 -.209 9.872 13ACtZ(,'710Uyl) L ,.-UAL r•VTGE ( KMI ,f, •,^ PLUM-OrSERVER DISTANCE (Ki1'l) 30.00 ( NO2) INTECr'►f. BLUE-rtED RATIO CONTPU T DELTA M I .OE+02 11.000 -.000 .000 2.n--+n2 1.000 -.000 .000 5.PC--:02 1.000 -.000 .001 1.0E+03 1.000 -.000 .001 2.OE+03 1.300 -.000 .002 3.00+93 1.000 -.000 .0:)5 1.0E+04 1.000 -.000 .010 2.0E+04 1.000 -.000 .021 3.0E+04 .999 -.001 .051 N 1.Ory05 .998 -.002 .101 0 2.OE+05 .997 -.003 .195 5.0E+05 .994 -.008 .445 I.0E+06 .990 -.015 .7T4 2.0E+06 .987 -.027 1.306 5.OE+�16 .990 -.0 ►4 2.449 I.OE+07 .999 -.077 3.515 2.0E+07 1.016 -.092 4.309 5.0E•*07 1.061 -.096 5.036 BACKGROUND VISUAL RANGE (RM 50.00 PLUTIE-OBSERVER DISTANCE (101) 40.00 (NO) INTEGRAL BLUE -RED RATIO CONTRAST DELTA E ( UG/M:.tx'2) 1.0E+02 1.000 -.000 .000 2.0E+02 1.000 .000 .000 3.0E+02 1.000 -.000 .000 l.©E+03 1.000 -.000 .000 ".OE-eO3 1.000 - . OGO .001 5.OE+()3 1.000 -.000 .002 1 .0&-04 1.000 -.000 .004 2.0E+04 1.000 -.000 .007 S.OE+04 1.000 -.000 .018 �v 1.0E+05 1.000 -.001 .031E J 2.0E+05 .999 -.001 .071 3.0E+03 .999 -.003 .168 1.0E+06 .998 -.007 .313 3.0E+06 .998 -.012 .567 5.OE+96 1.000 -.025 1.158 1.0E+07 1.006 -.035 1.699 ..OE+07 1.016 -.042 2.147 5.0E+07 1.042 -.044 2.614 BACKGROUND VISUAL RANGE (KM) 50.00 PLUME -OBSERVER DISTANCE (KM) 50.00 ( NO2) I NTEGML BLUE-RrD ILYT I O CONTRAST DELTA E ( UGiM:r*2) 1.0E+02 1.000 -.000 .000 2.0E+02 1.000 -.000 .000 S.OE+92 1.000 -.000 .000 1.0E+03 1.000 -.000 .000 2.0E+03 1.000 -.000 .000 3.0E+03 1.000 -.000 .001 1.0E+34 1.0eo -.000 .002 .0CY04 1.000 -.000 .003 3.0E+04 1.000 -.000 .008 iv 1.0E+05 1.000 -.000 .015 O N 2.0E+05 1.000 -.001 5.0E+05 1.000 -.002 .073 1.0E+06 1.000 -.003 .141 2.0E+06 1.000 -.006 .266 3.0E+06 1.002 -.011 .556 1.0E+07 1.005 -.016 .626 2.0E+07 1.1)11 - . 019 1.076 5.0 +07 1.026 -.020 1.364 DACRGROU" VISUAL RANGE (RPI) 1".0 PL IM-OBSERVER DISTANCE (KTI) 5.00 (NO-29 IMMORAL DI..X7E-RED RATIO CONTRAST DLLTA E ( 7JG/PI.**2) 1.0E+02 1.000 -.000 .002 2.0C+02 1.000 -.000 .005 3.0E+02 1.000 -.007 .012 1.0C+03 .999 -.000 .024 2.0E+03 .999 -.000 .047 5.0E+03 .997 -.001 .116 1 .0E+04 . ^94 - . 001 2.0E+04 .980 -.003 .470 3.0E+01 .970 -.007 1.167 C 1.0E+03 .941 -.013 2.300 w 2.©E+05 .006 -.027 4.514 3.0E+73 .750 - . 063 10.536 1.0E+06 .592 -.125 16.892 . 0E+06 .427 - . 231 30.2.33 S.00+06 .'329 -.462 41.307 i.OG+07 .334 -.664 43.263 2.0E+07 .361 -.792 44.532 3.0E+07 .453 -.022 43.992 BACKGROUND VISUAL RANGE MM) 10n.o PL UI•r-OESERVLII DISTANCE (lCPD 10.00 (1;02) INTEGMAL BLUE -RED IL'ITIO CONTKAUST DMLTA F. 1.OE+03 1.000 -.000 .002 2.OE+02 1.000 -.000 .003 .@Z+0: 1.000 -.000 .009 1.OE+03 1.000 -.000 .017 .999 - . 090 .034 5.OE+03 .998 -.001 .086 1 .OE+f)4 .996 - . 001 .171 3.0E+04 .992 -.0021 .341 5.00+04 .979 -.006 .845 1.0E+05 .959 -.011 1.668 CD 3.0E+05 .922 -.022 3.246 3.OE+05 .02O •-.034 7.476 1.0E+06 .719 -.103 13.060 3.0E+06 .600 -.199 20.001 3.OE+06 .545 -.380 26.427 1.0E+07 .559 -.G46 29.246 3.0E+07 .598 -.631 31.489 3.0E+07 .726 -.676 32.139 DACKCROUAI) VISUAL RANCE (KH) 100.0 PLUPIE-OBSERVER DISTANCE (KM) 13.00 (NO2)INTEGRAL BLUE -RED RATIO CONTRAST DELTA E ( UC/P1**2) I.OE+02 1.000 -.000 .001 2.0E+02 1.000 -.000 .002 5.00+02 1.000 -.000 .006 1.0E+03 1.000 -.000 .012 2.00+03 .999 -.000 .025 5.0E+03 .999 -.000 • .062 1.0E+04 .997 -.001 .124 2.0E+04 .994 -.002 .247 S.OE+04 .986 -.005 .613 ro 1.0E+03 .972 -.009 1.207 0 ol 2.0E+05 .946 -.018 2.34:-0 5.0E+05 .0182 -.044 5.335 1.0E+06 .807 -.085 9.177 2.0E+06 .732 -.156 13.625 5.0E+06 .694 -.312 10.429 1.0E+07 .711 -.44) 21.663 2.0E+07 .754 -.336 24.065 3.O +07 .839 -.356 25.152 BACIMHOUND VISUAL RANGE ("D 100.0 PLUM -OBSERVER DISTAUCE (KH) 20.00 ( N92) INTEGR'3L BLT1E-RED RATIO CONTRASRT DELTA E ( UG/M#,.k2 ) 1.0Z+02 1.000 -.000 .001 2.0E-1-02 1.000 -.000 .002 5.0E+02 1.000 -.000 .0031 1. OE•,•03 1.000 -.000 .009 2.0E+03 1.006 -.000 .016 3.0E+03 .999 -.000 .045 1.0E+04 .998 -.001 .090 2.0E+04 .996 -.002 .130 3.0E+04 .990 -.004 .445 tv 1.0E+05 .931 -.007 .874 O 2.0E+03 .963 -.015 1.691 U.OE+05 .919 -.035 3.329 1.0E+06 .860 -.070 6.328 2.0E+06 .817 -.128 9.766 3.0C+06 .795 -.257 13.532 1.0E+07 .313 -.370 16.789 2.0E+07 .656 -.441 19.091 5.0E+07 .966 -.457 20.332 BACKCROURD VISUAL RANGE (IUD 100.0 PLM1E-OBSERVER DISTANCE (KM) 30.00 ( N92) I NTEGITUL BLUE -RED RATIO CONTRA; 3T D^LTA E (UG/?,P"*2) 1.0E+02 1.000 -.009 .000 2.0E+02 1.000 -.000 .001 5 . ')E+0 : 1.000 -.000 .002 1. 011+03 1.000 -.000 .005 2.OE+03 1.000 -.009 .010 5.OE+03 1.000 -.000 .024 l.OE+04 .199 -.001 .048 2.OE+94 .998 -.001 .095 3.0E+04 .995 -.003 .233 1.00+03 .991 -.005 .462 v 2.0E+05 .933 -.010 .891 5.OE+05 .962 -.024 2.007 1.0E+06 .739 -.047 3.413 2.0E+06 .916 -.087 5.190 5.0E+06 .910 -.174 8.056 1.0-C-+07 .928 -.259 10.828 2.0E+07 .964 -.290 12.710 3.0E+07 1.071 -.310 13.942 BACKGROUND VISUAL RANGE (KM) 100.0 PLUM -OBSERVER DISTANCE (KM) 40.00 (NO2)INTECItAL BLUE -RED RATIO CONTRAST DELTA E ( LrG/N**2) 1.0E+02 1.000 -.000 .000 2.GE+02 1.000 .000 .001 5.0E+02 1.000 -.000 .001 1.0E+03 1.000 -.000 .003 2.0C+03 1.000 -.000 .005 5.OE+03 1.000 -.000 .013 1.0E+04 1.000 -.000 .026 2.0E+04 .999 -.001 .051 5.0E+04 .998 -.002 .126 1.0E+05 .996 -.003 .248 ON 0O 2.0E+05 .992 -.007 .479 5.0E+03 .982 -.017 1.035 1.0E+06 .972 -.032 1.072 2.0E+06 .962 -.059 2.981 5.0E+06 .963 -.118 5.205 1.0E+07 .978 -.169 7.321 2.0E+07 1.007 -.202 8.770 5.0E+07 1.089 -.209 9.852 BACKCROUND VISUAL RANGE (NM 100.0 PLUME -OBSERVER DISTANCE (KH) 50.00 (NO2) INTE9PAL BLUE -TIED r&ATIO CONTR&ST DELTA E (UG/H:;:*2) I.0E+02 1.000 -.000 .000 2.0E+()2 1.000 -.000 .000 3.0E+02 1.000 -.000 .001 1.0E+03 1.000 -.000 .001 2.OE+03 1.000 -.000 .003 5.0F,+03 !.000 -.000 .007 1.0T+04 1.000 -.000 .014 2.OL+04 l . ". 0 -.000 .028 5.0E+04 .999 -.001 .070 ro 1.OE+05 .990 -.O03 .138 0 3.0E+Dv .996 -.005 .267 5.0E+05 .992 -.011 .613 1.0E+06 .988 -.022 1.090 2.0E+06 .984 - . 040 1 .84.2 5.0E+06 .987 -.080 3.512 1.OE+07 .999 -.115 5.051 2.0E+07 1.022 -.137 6.144 � 3.0E+07 1.084 -.142 7.051 BACKGROUND VISUAL. RANGE (FYI) 100. 9 PLUM-00SE IX-R DISTANCE (KM) 1ra0.0 (NO2) INTErItAL rL(il: ^?U RATIO CONTRAST DELTA E ( US;✓rt>t*2) I.0E+02 1.000 -.000 .000 2.0E+02 1.000 -.000 .000 5.0E+02 1.000 -.000 .000 I I.OE+03 1.000 -.000 .000 2.0E+03 1.1000 -.000 .000 5.@E+03 1.000 -.000 .001 1.0E+04 1.000 -.000 .002 2.0E+04 1.000 -.000 .003 5.0E+04 1.000 -.000 .00a N 1.OE+05 1.000 -.0011 .015 2.0E+05 1.O00 -.O01 .030 3.0E+05 1.000 -.002 .075 1.O +06 1.000 -.003 .146 2.OZ+06 1.001 -.006 .276 3.0E+06 1.003 -.01:: .569 1.0E+07 1.006 -.017 .641 2.0E+07 1.012 -.02.9 1.098 5.0C-1.07 1.027 - . 020 1.392 BACKGROUND VISUAL RANGE (XM 150.0 PLUME -OBSERVER DISTANCE (KM) 5.00 (NO2)INTEGRAL BLUE-rM RATIO CONTRA:;T DELTA E (UGiM**2) 1.8E+02 1.000 -.000 .003 2.0E+02 1.000 -.000 .005 5.0E+02 1.000 -.000 .013 I.OE+03 .999 -.000 .025 2.0E+03 .999 -.000 .051 5.©E+03 .997 -.001 .127 1.0E+04 .993 -.001 .253 2.OZ+04 .986 -.003 .506 3.0E+04 .967 -.007 1.256 ro I.OE+05 .935 -.014 2.467 -' 2.@E+03 .875 -.028 4.373 3.0E+03 .725 -.069 11.460 1.0E+06 .530 -.133 20.705 2.4E+06 .360 -.247 33.622 5.00+06 .257 -.493 47.793 I.OE+07 .259 -.709 49.714 2.0E+07 .281 -.843 50.786 5.0^+07 .338 -.870 49.940 BACKGROUND V I SUAL RRANCE (r4'1) 150.0 PLUM-OESERSjER DISTANCE (FUI) 10.00 (NO2) I FTEGRAL BLUE-^.ED Iu1T I O CONT11.10T DELTA I. ( L"G/Pt**2) I.OE+02 1.000 -.000 .002 2.0E+02 1.000 -.000 .004 �.0E+02 1.000 -.000 .010 1.0E+03 .999 -.000 .020 2.OE+03 .999 -.000 .040 5.0E+03 .997 -.001 .101 1.0E+04 .995 -.001 .202 2.OE+04 .990 -.003 .402 5.0E+04 .975 -.006 .990 N 1.0E+05 .930 -.013 1.972 N 2.0E+05 .905 -.025 3.1148 5.0E+05 .791 -.061 8.937 i .0E+06 .659 -. 117 15.1-414 2.0E+06 .523 -.216 0-4.044 5.0E+06 .443 -.433 33.292 I.OE+07 .434 -.622 36.091 2.0E+07 .439 -.742 1-08.543 5.0E+07 .606 -.771 38.918 PAS :tGn"UND `•ISTrAI. RANGE (Yr1) 1.15". e r'LUME-OPRZE111•17.•R (rUD 15.00:o (NO2) INTEGRAL BLUE -RED 1tA'1'10 CONTRAt4'1' DELTA E (UG/N**2) 1 .OE+02 1.000 - . ()7(1 .002 2.OV-+02 1 .0^0 - . Q() > . or)-i 3.0E+02 1.000 - . GOO . W)"I 1.0E+03 1 .000 - . 011 0 .01() 2.OE+03 .9-�9 - . o"Y% . 0-32 3.OE+03 .99r3 - . 001 .01;() 1.OL+04 .996 -.001 .I("PO 2.0E+04 .9%)2 •-.002' ;='►► 3.OE+04 .931 - . 0;) ; .793 N 1 .4E+0z; .962 - . 0 : 1 1 . ;i6Ar 5.OE }0:i . 8-12 - . 07.4 7.001 1 . o E+0 6 . 7 :-2 - . 103 12.233 2.0 Z+()6 6219 - . 1 n(1 1 0.73'2 ! . OG+07 .599 - . 1.7 26.416 2. OE+07 .1641 . 05:.! ;31 . ,2(; 5 171.43+?7 .773 -.077 32,. 190 BACKGROUND VISUAL RANGE (M) 150.0 I' LUM-OBSERVER DISTANCE (IUD 20.00 ( NO2) INTEV,P.AL BL':';-RCA RATIO CONTRAST DELTA E 1.00+02 1.000 -.000 .001 2.OE+�)2 1.000 -.007 .O03 5. ?Z+02 1.000 -.000 •0 )6 I.O ,+03 1.000 -.000 .010, 2.0E+03 .999 -.000 .026 8.0E+03 .999 -.000 .064 1.0E+04 .997 -.001 .128 2.OE+04 .994 -.0O3 .2155 3 . QE+04 .935 - . 007) . 631 N 1 .00+05 .971 If) t . 242 � 2.0E+('+3 .')•,a - . O l n 2 ..,• 10 3. ©E+o5 .880 -. 047 5.50Z, I.OZ+06 .805 -.090 9.493 2.OL+06 .728 -.167 14.333 3.0E+06 .6i:9 - . 334 19.4Fi4 I .O L+07 .708 - . 439 23.2911 3. Q%P+07 .7 ,3 - . 572 26.2102 5.O +07 .996 -.394 27.393 ]BACKGROUND VISUAL. RANGE (KN) 150.0 PLUPIE-OBSERVER D I STANCE ( ICN) 30.00 (NM)INTIF.GRAL BLUE -RED RATIO CONTRAST DELTA E ( UG1lk*q-2) 1.0E+02 1.000 -.000 .001 2.0E+02 1.000 -.000 .002 5.9E+02 1.000 -.009 .004 1.0E+03 1.000 -.000 .008 2.0E+03 1.03U -.000 .016 3.0E+03 .979 -.000 .041 1.0E+04 .993 -.001 .081 2.OL+04 .997 -.0021 .161 3.0E+04 .992 -.O04 .400 N I.9E105 .964 -.007 .766 2.OE+fl3 .969 -.015 1.520 5.0E+03 .931 -.036 3.441 1. OE+06 .869 - . F)70 5.875 2.OE+06 .8116 - . 129 8.667 U . OE•' 06 •29 - . 357 12.904 1 .0E+ey7 .43 ..19 - . 370 16.727 2.00+07 .C94 -.441 19.372 5.OZ+07 1.029 -.453 20.7211 BACKGROUND VISUAL RANrE (KM) 15o.0 PLUME-OBSER7ER DISTANCE (KPD 40.00 (NO2)INTEGRAL BLUE -RED RATi0 CONTRAST DELTA E ( UG/Mk*2) i.OE+92 1.000 -.000 .001 2.0E+0.3 1.000 -.000 .001 3.0t,+02 1.000 -.000 .003 1 .02+03 1.090 -.000 .005 2 . -21 +03 1.000 -.000 .010 5.9E+03 1.000 -.009 .026 1.0E+04 .999 -.001 .052 2.NE+04 .998 -.001 .103 3.0E+04 .995 -.003 .235 N I .0E+05 .991 - . O()6 .501 ON 2.0E+05 .982 -.011 .967 3.0E+05 .961 -.026 2.186 1.0E+06 .937 -.054 3.738 2.9E+06 .914 -.099 5.754 5.0E+06 .909 -.193 9.209 I.OE+07 .920 - . 2115 12.537 2.0E+07 .968 -.340 14.640 5.0E+07 1.086 -.333 16.165 bAck(;tt6WM V t soAL Mkok (kN) 1 se . 8 PLUIIE-OBSERVER DISTANCE (IUD 50.00 ( R02) I NTECRAL SLUE -ICED RATIO CONTRAST DELTA E ( UG/PI*:92 ) 1.0E+02 1.060 -.000 .000 2.0E+02 1.000 -.000 .001 5.8E+02 1.000 -.090 .002 1.0E+03 1.000 -.000 .003 2.0E+03 1.000 -.000 .007 5.0E+03 1.000 -.000 .017 1.0E+04 .999 -.030 .033 2.6E+04 .999 -.001 .067 5.0E+04 .997 -.002 .165 �y 1.0E+05 .995 -.004 .323 v 2.0E+03 .990 -.009 .625 3.4E+03 .978 -.022 1.419 i.OE+06 .965 -.041 2.437 2.0E+06 .952 -.077 3.926 3.0E+06 .953 -.153 6.677 i.OE+07 .970 -.220 9.696 2.OE+07 1.003 -.262 11.566 5.0E+47 1.1404 -.272 12.739 BACKGROUND VISUAL ►LANCE (K'i) 150.0 PLUDIZ-OBSER'JI.Pi. ( `"(12) 1NTE(MIL BLUE -'MILD RATIO CONTPUST DELTA E !.4E+02 1.000 -.000 .000 2.0E+02 I.000 -.000 .000 3.0E+02 1.000 -.000 .000 I.OE+03 1.000 -.000 .001 2.Oi:+03 1.000 -.001) .001 G . OE+03 1 .00YO - . 000 .003 1 . of-" O-S 1.000 - . 000 .006 -.0^+04 1.000 -.030 .011 5.0r,+04 1.000 -.001 .026 N I.OE+05 1.000 -.001 .056 OD mE+05 1 . CCO - . 002 . 1 1 1 5.00+05 .999 -.036 .271 I . oC+06 .999 - . 01 1 .520 2. nir;+06 .999 - . 021 . IDZ 1 G . OE+06 1.003 - . 0 -tom 1.994, 1.0 +07 1.011 -.061 2.033 2.0E+07 1.023 - . 0 72 :3.571 G . OZ+0^7 1.062 - . 075 4.190 BACKGROUND VISUAL RANGE OM) 150.9 PLUME-0,*.3SERVER D I STAN::E (M) 150.0 (NO2) I1rT MIML BLUE -RED RATIO COMMAST DELTA E ( UriM**2) 1.0E-0:. 1.1700 -.000 .000 2. OE+02 1.000 -.000 .000 0.0E+0-1'b 1.000 -.000 .000 1.0E+03 1.000 -.000 .00() 2.0E+03 1.000 -.001 .000 3.0E+03 1.000 -.000 .001 I.OE+04 -1.000 -.000 .002 2.0E+04 1.000 -.000 .003 5.0E+04 1.000 -.000 .00A N 1.0E+05 1.000 -.000 .017 1.009 -.001 .034 5.0E+03 1.000 -1002 .083 1. OE+OCR 1.009 - . 003 .160 2.OE+06 1.001 -.006 .300 0.0E+06 1.002 -.Oi-l', .603 1.0E+07 1.003 - . 017 3.0E+07 1.010 -.021 1.122 5.0E+07 1.0123 -.021 1.377 BACICGP.()UND VISUAL RANGE (KK) 209.0 PLUrI.-()=,,SERVER I)IST,1NCE OUT) 5.00 ( Pi(*2) INTI:CP.1L Ci,[Jf;-='.?;D I:AT?O CONTRAST DELTA E 1.OL+02 1.000 -.000 .003 2.OE+0:: 1.000 - . 00€) . M 3.0E+02 1.009 -.000 .013 1.0E+03 .999 -.000 .026 2. 0Z+03 .999 -.000 5.OE+G3 . �11)6 - . 001 . 1102 1.0E+04 .993 -.001 .264 2.0E+04 .936 -.003 .327 3.0E+04 .965 - . 007 1.310 1.00+03 .931 -.013 2.594 N N /� Co 2.0E+0v • [ld69 -. ©219 //��I� . 5 . 037 G . OL+05 .711 - . 07.^_ 11.999 1.0E+06 .520 -.13•'3 21.794 2.0E+06 .337 -.253 36.003 5.OE+06 ..'fin 19 - . 509 G21. 093 1.0E+07 .219 - . 73.^. 54 . 2 7 3.0E+07 .230 -.EZ3 55.169 5.OZ+07 .305 -.907 94.193 BACKGROUND VISUAL RANGE ( KM 200.0 YLUIE-OESERVEn DISTANCE (KK) 10.00 ( iIQ2) I }TITI�:GRAL BLUE, -RED RATIO CONTRAST DELTA E 1.0E+02 1.000 -.000 .002 3.0E+02 1.000 -.000 .004 5.0E+021 1.000 -.000 .011 1.0E+03 .999 -.000 .022 3.0E+03 .999 - . 60.0 .0,04 5.0C+03 .997 -.001 .110 1.00+04 .994 -.001 .220 2.00+04 .939 -.003 .439 5.CC+04 .972 -.E07 1.090 N 1.0E+03 .945 -.01:3 2.154 2.0C+03 .895 -.027 4.211 5.OE+05 .770 -.065 9.620 1.OE+06 .624 - . 125 17.529 2.0z+06 .473 -.231 27.936 5.00+06 .384 -.462 38.112 1.0E+07 .392 -.664 40.945 2.0 +07 .424 -.792 43.563 5.0:;+07 .532 - . L'22 43.771 BACKGRO1JUD V 1 ST1.AL RANGE (M) 200.0 PLUME -O z,ERVF'.rt DISTANCE (KI-1) 15.00 ( NO2) IWTEGRAL BLUI?-TIED RATIO CONTRAST DELTA E ( UG✓M**2) 1.0E+02 1.000 -.000 .002 2.OE+02 1.000 -.000 .00.1 3.CE+02 1.000 -.000 .009 1 .0E+03 1.000 -.000 .010 .3.0E+03 .999 -.OGC) .037 5.0Z+03 .990 -.0+01 .092 1 .0E+04 . 395 - . 001 .103 2.00+04 .991 - . 002 .:366 5.0E-: 04 .973 - . 006 .907 N 1.0E+05 .956 -.012 1.790 N N 2.0E+05 .917 -.024 .3.490 5.0E+05 .:317 - . GG9 0.076 1.0E+06 .701 -.113 14.206 2.0E+06 .582 -.209 22.114 5.OE•+-06 .515 - . 419 29.669 1.0E-07 .528 - . 602 33.313 3.0E+07 .568 -.710 36.516 5.0E+07 .700 -.746 37.301 BACKGROUND VISUAL. I1ANGE (Him 200.0 PLMM-OBSERVER DISTANCE (KM 20.00 (W02)INTEGRAL BLUE -RED RATIO CONTRAST DELTA E ( UGiMW-,2 ) 1.0E+02 1.000 -.000 .002 2.0E+02 1.000 -.000 .003 5.OE+02 1.000 -.000 .008 1.0E+03 1.000 -.000 .015 2.0E+03 .999 -.000 .031 5.0E+03 .998 -.001 .076 1.0E+04 .996 -.001 .153 2.0E+04 .993 -.002 .305 5.0E+04 .962 -.006 .755 N 1.0E+05 .963 -.011 1.489 N w 2.0E+05 .934 -.022 2.695 5.0E+05 .854 -.053 6.654 1.0E+06 .762 -.103 11.585 2.0E+06 .660 -.190 17.765 3.0E+06 .618 -.380 23.969 1.0E+07 .635 -.546 28.141 2.0E+07 .680 -.631 31.51E 5.0E+07 .324 -.676 32.613 BACKGROUND VISUAL MANGE (KM) 200.0 PLUME -OBSERVER DISTANCE (KM) 30.00 (Nn2)INTEGRAL BLUE -RED RATIO CONTILRST DELTA E ( UGiN-x:r•2 ) 1.0E+02 1.000 -.000 .O01 2.0E+02 1.000 -.000 .002 S.OE+02 1.000 -.000 .O05 I.01:+03 1.000 -.000 .011 2.0E+03 1.000 -.009 .021 5.0E+03 .999 -.000 .053 1.0 +04 .990 -.001 .106 2.0E+04 .995 -.002 .212 5.0E+04 .969 -.005 .524 1.0E+05 .978 -.009 1.032 ro 2.0E+05 .958 -.016 .2.001 5.0E+05 .908 -.044. 4.555 I.OE+06 .350 a -.085 7.830 2.0E+06 .792 -.156 11.669 3.0E+06 .766 - . 312 16.636 1.0E+07 .786 -.449 21.355 2.4E+07 .333 -.536 24.601 5.0E+07 .9813 -.556 25.931 BAD[{GROUND VISUAL RANGE (K?f) 200.0 PLUI1E-OBSER4TIi DISTANCE (KM) 40.00 (NOS) IMM-CrCLUE-P.ED IL1TI0 CONTRAST DELTA E (UG/M�*2) 1.0E+02 1.O00 -.000 .001 2.OE+02 1.000 -.000 .001 5.0E+02 1.000 -.000 .004 t.OE+03 1.000 -.000 .007 2.0E+03 1.000 -.000 .015 5.03+03 .999 -.000 .037 1.0E+04 .999 -.00t .074 2.0E+04 .997 -.002 .140 5.0E+04 .993 -.004 .366 N 1.0E+05 .906 -.007 .720 N 2.0E+03 .973 -.015 1.392 5.7E+05 .942 -.036 3.154 1.OE+06 .906 -.070 5.403 2.0E+06 .670 -.120 6.255 5.0E+06 .850 -.257 12.639 1.0E+07 .079 -.369 16.949 2.0E+07 .925 -.441 19.849 5.OE+07 1.063 -.457 21.241 BACKGROUND VISUAL RANGE (KM) 200.0 PLUPIE-OBSERVER DISTr'1NCE (M) 50.00 (F03) INTE''I'_1L F LUE-M-9 rATIO CONTPL�IST DELTA E � �) 1.00+02 1.000 -.000 .001 2.0E+02 1.000 -.000 .001 .5.OG+02 !.000 -.000 .003 1.OZ+03 1.000 -.000 .003 2.OE+03 1.000 -.010 .010 .0E+03 1.000 -.000 .026 1.0E+04 .999 -.001 .052 2.0E+04 .9913 -.001 .104 5.0E+04 .996 -.OG3 .257 1.0E+05 .991 -.006 .506 tv N 2. OE+05 .903 - . O 12 .9178 5.0E+05 .904 - . 030 1.0E+06 .941 -.037 3.315 2.0E+06 .920 -.106 5.965 3.0E+06 .916 -.211 9.909 1. 0E- 07 .936 - . 304 13.769 ?.. 0;;+07 .973 - . 362 16.2$3a 5.0+07 1.102 - . 376 ! 7.633 C:1--:CrROTJND VISUAL RANGE ( KM) 200.0 P&UFm-onsimi-li L`. D I STM-ICE MTD t OO.0 ( W12) IN EXIML BLOC-.", D MTIO CONTRAST DELTA E ( TJG/PI* *3) 1.0E+02 1.000 -.000 .090 2.0E+02 1.000 -.000 .000 5.0E+02 1.000 -.000 .001 1.0E+03 1.000 -.000 .001 2.0 +03 1.000 -.000 .002 G.OE+03 1.COO -.000 .006 1.0E+04 1.000 -.000 .012 2.00+04 1.000 -.000 .023 5.0E+04 1.000 -.001 .053 N 1.0E+05 .999 -.002 .114 N v 2.0E+05 .999 - . OO.a .225 5.0E+05 .997 -.011 .537 i.GE+06 .993 -.022 1.010 2.0E+06 .993 - . 040 1 .64.5 5.0E+06 1.000 -.000 3.746 1.0E+07 1.011 -.114 5.39a 2.00+07 1.032 -.136 6.523 5.0E+07 1.090 -.142 7.34-0 nACM, PLTND VISUAL FLANGE (KM) 200.0 PLUPM-OBSERVER, I)ISTMICE (Iql) 159.0 MOM INTEG.^AL BLUE-M- 9 I:ATIO CONTMST DELTA E ( liG/Pl*'' 2) I.OE+02 1.000 -.000 .000 2.00,+02 1.300 -.000 .000 5.0E+0.2 1.000 -.000 .090 I.OL+03 1.000 -.000 .000 2.0E+03 1.000 -.000 .001 3.0E+03 1.000 -.000 .002 1.Gr-+04 1.000 -.000 .004 2.0E+04 1.000 -.000 .00a 3.0E+04 1.000 -.000 .021 N 1.0E+05 1.000 -.001 .042 N 00 3.0E+05 1.000 -.002 .Cii3 5.00+05 1.000 -.004 .121.03 1.00+06 1.000 -.00U . 393 2.OE•1-06 1.001 - . O l g .736 5.0E+06 1.004 - . 0?.() 1.491 1. OE•; 07 1.003 - . 043 2.134 �.OE+O I .f)III .O' 1 2.61.11 5. 0+07 1 . �l':4 - . OJ3 3.045 BACKCGROUNIP VISUAL RANGE (KPI) 200.0 PLUTM-OBSERVER DIST1TiCE (KM) 200.0 (1192) INTEGRAL PPLUE-RED RATIO CONTRAST DELTA E (UG/M**2) 1.0E+02 1.000 -.000 .000 2.0E+02 1.000 -.000 .000 3.0E+02 1.000 -.000 .000 1.0E+03 1.000 -.000 .000 2.0E+03 1.000 -.000 .000 5.0E+03 1.000 -.000 .001 1.0E+04 1.000 -.000 .003 2.0E+04 1.000 -.000 .003 5.0E+04 1.000 -.000 .003 N 1.0E+05 1.000 -.000 .016 N 3.0E+05 1.000 -.001 .032 3.0E+05 1.000 -.002 .079 1.0E+06 1.000 -.003 .134 2.0E+06 1.000 -.006 .287 3.0E+06 1.001 -.011 .575 1.0+07 1.003 -.016 .016 2.0E+07 1.006 -.020 .995 5.0E+07 1.013 -.020 1.146 BACKGROUND VISUAL RANGE (Krt) 250.0 PLUM-OUSEMElt DISTAKCE 0UD 5.00 (NO2) I IM' AL BLUE -RED IL'1T I O CONTRAST Di .LTA r 1.0E+02 1.000 -,00:i .003 2 . 0E+02 1.000 -.000 .005. 5.0E+02 1.000 -.000 .O14 1.0E+03 .999 -.000 .027 2.AE+03 .999 -.000 .054 3.00+03 .996 -.001 .136 1.0E+04 .993 -.002 .271 2.0E+04 .985 -.003 .342 3.0E+04 .964 -.008. 1.347 . N 1.0E+05 .929 -.015 .2.666 w 2.0E+05 .865 -.030 5.236 5.0E+05 .703 -.073 12.372 1.4E+06 .314 -.140 22.540 2.0E+06 .317 -.260 37.323 5.0E+06 .195 -.519 55.254 1.0E+07 .194 -.747 57.677 2.0"L+07 .211 -.890 58.499 3.0C+07 .272 -.924 57.464 N W BACKGROUND VISUAL RANGE (KM) 250.0 PLUM -OBSERVER DISTANCE (KK) 10.00 (NO2) INTr,r._TLAL BLUE -RED RATIO CONTI ST DELTA E (UG/M**2) 1.0E+02 1.000 -.000 .002 2.0E+02 1.000 -.000 .005 5.0E+02 1.000 -.000 .012 1.0E+03 .999 -.000 .023 2.0E+03 .999 -.000 .047 5.0E+03 .997 -.001 .116 I.OE+04 .994 -.001 .232 2.0E+04 .988 -.003 .464 5.0E+04 .970 -.007 1.152 1.0E+05 .942 -.014 2.279 2.QE+08 .689 -.020 4.460 5.0E+05 .756 -.063 10.441 1.0E+06 .601 -.130 18.721 2.OE4 06 .441 - . 240 30.137 5.0E+06 .345 -.460 41.743 1.0E+07 .352 -.690 44.645 2.0E+07 .301 -.823 47.390 3.0E+07 .462 -.854 47.501 BACKGROUNI) VISUAL RANGE (KM) 2 sn.0 PLUM,-OBS::ny)r, L DISTANCE ( I'M) 1 -P.00 (NO2)INTEGRAL BLUE -RED RATIO CONTRAST DELTA E (UG/K**2) 1.0E+02 1.000 -.000 .002 2.OE+02 1.000 -.0011) .00 5.0E+02 1.000 -.000 .010 1 .00'L03 i.000 -.000 2.OG+03 .999 -.000 .040 5.Oi•1-03 .990 -.001 .100 1.0Z+04 .995 -.001 .199 2.OE+04 .990 -.001 .397 5.0E+04 .976 -.006 .986 N 1.0E+05 .952 -.013 1.94's w N 2.00+05 .909 -.026 3.802 5.0E+05 .300 -.062 8.832 1.0E+06 .673 -.120 15.636 2.0E+06 .543 -.222 24.601 5.0E+06 .468 -.443 33.327 1.0E+07 .430 -.638 37.070 2.0E+07 .517 -.761 40.565 5.0E+07 .644 -.790 41.24a BACKGROUND VISUAL RANGE (KM) 250.0 PLCTIIE-OCSEnvl ;R D i STANCE (KH) 20.00 ( Re?) I NTrG1tAL BLUE -PAD I -LIT 17 COIIT'u T.0 DELTA E ( UG/r'uk:k2) 1. eE+02 1.000 -.000 .002 r.OE•r02 1.000 -.007 .003 5.0E+02 1.000 -.000 .009 1.GE+03 1.000 -.000 .017 2.0E+03 .999 -.000 .034 5.0E+03 .998 -.001 .085 1.0E+04 .996 -.001 .171 2.00i04 . (; 92 - . 002 .340 5.OE+04 .9010 -.0015 .84-4 iv I.OE+03 .961 - . 012 1.666 w w 2.00+05 .925 -.024 3.244 U . O1's+05 .836 - . 058 7.489 1.0E+06 .733 -.111 13.124 2.0E+06 .626 -.205 20.329 U.QE+06 .560 -.410 27.512 1.0E+07 .534 -.590 31.906 2.0E+07 .627 -.703 35.668 3.0E+07 .769 -.730 36.675 I3At7'.:GROUND VISUAI. BARGE ( KN) 259. 0 PLUTIZ-03SER`JER DISTANCE (KM) 30.00 (1*41'3) INTI„RAL I;I: TE-IL^D PATIO COPITP.A'-T DELTA E 1.OZ-02 1.000 -.000 .001 2.0E+02 1.000 -.009 .003 5.0 J+02 1.000' -.000 .006 I.OG+03 1.000 -.000 .013 2.0E+03 .999 -.000 .025 5 . C::4 n3 .999 - . 001 .063 1 .0E+04 .997 - . 001 . 125 2.00+04 .1M -.002 .250 5.0E-1.04 .937 - . 005 .620 N 1 .0E+05 .974 - . 010 1. `,'.21 w 2.0E+05 .950 - . 020 2.131_ 0 S.OE+05 .690 -.049 5.419 1.0E+06 .821 -.095 9.370 2.0E+06 .751 -.175 14.292 5.00+06 .717 - . 350 20.039 1.0E+07 .737 -.504 25.0.14 2.OE+07 .735 -.601 23.787 5.03+07 .939 -.623 30.091 AACKCROURD VISUAL RANGE ( IUD 2110.0 PLUNK -OBSERVER DISTANCE (KM) 40.00 ( l?02) INTErP1AL BLUE -RED RATIO CONTRAST DELTA E ( UO/il**2) 1.0E+02 1.000 -.000 .001 2.0E+02 1.000 -.000 .002 5.0E+02 1.000 -.000 .005 1. eE,+03 1.000 -.000 .009 2.0E+03 1.000 -.000 .019 5.0C+03 .999 -.000 .046 1.0C+04 .9911 -.001 .093 2.0E+04 .996 -.002 .184 5.0C+04 .991 -.004 .457 ro I.OE+05 .982 -.009 .899 w cri 2.0E+05 .966 -.017 1.740 5.0E+05 .926 -.042 3.958 1.0E+06 .080 -.081 6.803 2.00+06 .835 -.150 10.390 5.0E+06 .a17 -.299 15.515 I.OE+07 .80..3 - . 430 20.520 2.0E+07 .037 - . 513 23.960 5.00+07 1.036 -.532 25.346 BACKGROUND VISUAL RANCE (KM) 250.0 PLUME -OBSERVER DISTANCE (KM) 50.00 ( NO2) I NTEGRAL BLUE -RED RATIO COnTRMT 0113. t'A F: (UG/M**2) 1.0E+02 1.000 -.000 .001 2.OE+02 1.000 -.000 .001 5.0E+02 1.000 -.000 .003 1.0E+03 1.000 -.000 .007 2.0E+03 1.000 -.000 .014 5.0E+03 .999 -.000 .034 1.0E+04 .999 -.001 .069 2.0E+04 .998 -.001 :137 5.0E+04 .994 -.004 .338 tv 1.0E+05 .988 -.007 .,665 w vn 2.0E+05 .978 -.015 1.287 5.0E+05 .951 -.036 2.922 1.0E+06 .920 -.069 5.020 2.0E+06 .891 -.128 7.793 5.0E+06 .863 -.255 12.514 1.0E+07 .904 -.367 17.197 2.0E+07 .950 -.430 20.265 5.0E+07 1.090 -.455 21.643 BACKGROUND VTSUAI. RANGE (KM) 250.0 FLMIE-OUSERVCR D 1 STANCE U(N) 100.0 (NO2) OWGRAL BLUE; -RED RATIO CONTPUST DELTA E ( UG/rl*w2) 1.0C+02 1.000 -.000 .000 2.0E+02 1.000 -.000 .000 3.0E+02 1.000 -.000 .001 1.0E+03 1.000 -.000 .002 2.0Z+03 1.000 -.000 .004 3.0E+03 1.000 -.000 .009 1.OZ+04 1.000 -.000 .010 2.0E+04 1.000 -.001 .037 5.0E+04 .999 -.002 .091 iv 1.0E+05 .999 - . 003 .180 w v 2.0E+05 .997 -.007 .352 5.0E+05 .994 -.016 .WO 1.0E+06 .991 -.031 1.533 2.0E+06 .969 -.050 2.740 5.0E+06 .994 -.115 5.4.84 1.0E+07 1.000 - . 166 7. MI'M 2.00+07 1.035 -.190 9.4139 3.00+07 I.110 -.200 10.420 DACKCROUAID VISUAL JWGL 1 i,i U X50. 0 PL(JPTE-OBSEWJ- E:lt DISTANCE ( Kul) 1 i0.0 tP702) IN'CF.0 Putt BLUE -RED RATIO CONTRIST DELTA E 1.0E+02 1.000 -.000 .000 2.0E+02 1.000 a -.000 .000 5.0E+02 1.000 -.000 ''' .000 1.0M+03 1.000 -.000 .001 ".OE-}03 1.000 -.000 .001 3.0E+03 1.000 -.000 .004 1.0E+04 1.000 -.000 .007 2.0E+04 1.000 -.000 .015 5.0E+04 1.000 -.001 .036 1.0E+05 1.000 -.001 .072 2.0E+05 1.000 -.003 .143 5.0E+05 .999 -.007 .349 1.0E+06 .999 -.014 .673 2.0E+06 1.000 -.026 1.256 5.0C+06 1.C64 -.051 2.549 1.0E+07 1.011 -.074 3.633 2.0E+07 1.024 -.0sa 4.381 5.0E+07 1.060 -.091 4.943 N W to BACKGROUND VISUAL RANGE (KM) 250.0 PLUME-03SERVER DISTANCE (KM) 200.0 ( I102) I NTEGRlAL BLUE-nED RATIO COWMIST DELTA E ( UG/PI**2) I.OE+02 1.000 .000 .000 2.0E+02 1.000 -.000 .000 5.0E+02 1.000 -.000 .000 1.0E+03 1.000 -.000 .000 2.0E+03 1.000 -.000 .001. 5.0E+03 1.000 -.000 .002 1.0E+04 1.000 -.000 .003 2.0E+04 1.000 -.000 .006 3.0E+04 1.000 -.000 .016 1.0E+03 1.000 -.001 .032 2.0E+05 1.000 -.091. .063 5.0E+05 1.000 -.003 .154 1.OE+06 1.000 -.006 .298 2.0E+06 1.000 -.011 .536 5.0E+06 1.002 -.022 1.115 1.0E+07 1.005 -.032 1.576 2.OE+07 1.010 -.038 1.095 5.©E+07 1.023 -.039 2.136 BACKGROUND VTSUAL RANGE (KM) 250.0 PLUME -OBSERVER DISTANCE (FJI) 250.0 ( NM INTEGRAL BLUE-nED IL'1TIO CONTR!' ST DELTA E ( UC/Pf.lt*2) 1.0E+02 1.000 -.000 .000 2.0E+02 1.000 -.000 .000 3.0E+02 1.007 .000 .000 i.OE+03 1.000 -.000 .000 2.0E+03 1.000 -.000 .000 5.oz+03 1.000 -.000 .001 1.0E+04 1.000 -.000 .001 3.0E+04 1.000 -.000 .003 5.0E+04 1.000 -.000 .007 1.0E+05 1.000 -.000 .014 A 3.0E+05 1.000 -.001 .027 5.0E+05 1.000 -.001 .066 1.0C+06 1.000 -.002 .125 2.00+06 .999 -.004 .228 5.0E+06 .999 -.009 .449 1.0E+07 1.000 -.012 .621 3.0E+07 1.000 -.015 .714 5.0E+07 1.000 -.015 .746 APPENDIX D REFERENCE FIGURES AND TABLES FOR POWER PLANT VISUAL IMPACTS This appendix presents figures and tables that show the calculated visual impacts of emissions from power plants of various sizes under dif- ferent meteorological and ambient conditions. These reference data are based on calculations made using the plume visibility model (PLUVUE). If one is evaluating a power plant (or another emissions source with similar particulate, S02, and NOx emission rates), one can identify the emission, meteorological, and background conditions shown here closest to the given case under evaluation. Alternatively, one can interpolate the values in the reference tables in this appendix to obtain a best estimate of a source's impact. These reference tables and figures would be used in a level-2 visibility screening analyses. The tables and figures are based on 96 PLUVUE runs for the permuta- tions of the following input parameters: > Power plant size: 500, 1000, and 2000 Mwe > Pasquill-Gifford stability category: C, D, E, F > Wind speed: 2.5 and 5.0 m/s > Background visual range: 20, 50, 100, and 200 km. The emissions used in this appendix are based on emission rates of controlled power plants meeting the EPA's New Source Performance Standards. Emission rates of 0.03, 0.3, and 0.6 pound per million Btu heat input --for particulates, S02, and NOx, respectively --were assumed. The emission rates for the 1000 Mwe and 2000 Mwe plants are simple multiples of those for the 500 Mwe case: The mass emission rates for a 500 Mwe power plant are as follows: 241 > Particles: 1.6 tons/day = 1.5 metric tons/day = 17 g/s > S02: = 16 tons/day = 14.5 metric tons/day = 168 g/s > NOx: 32 tons/day = 29 metric tons/day = 336 g/s. Other important input parameters for the PLUVUE runs used to generate the tables and figures in this appendix are summarized below: > Flue gas flow rate (per stack): > Flue gas temperature: > Ambient relative humidity: > Background ozone concentration: > Mixing depth: > Simulation date/time: > Plume -observer distance: > Scattering angle: > Line -of -sight orientation: 1,270,000 ft3/min = 599 m3/s 175OF = 353°K 40% 40 ppb 1000 m 23 September/10:00 a.m. Maximum of 5 km or a half -sector width (rp = 0.2 x) 900 Horizontal, perpendicular to the plume centerline. As noted, if the user has a situation in which conditions are between those used in this appendix, interpolation will yield a reasonable esti- mate cf_ impacts. However, if one has to extrapolate the results of this appendix, one should exercise extreme caution: Many visual impacts do not have a linear relationship with input conditions. 242 50OMW COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPED = 2.5 MIS BACKGROUND V I SUP?. R l GE = 20. KM PLUP - VISUAL PLUME PLUNK rowriuND OESi..::�r. P.P_.�GE CONTICeST PERCEPT- DIET"1ICE D13°AI'!CE REDUCTION BLUE -RED AT 0.55 IBILITY ( I'2D ( I_r?) (7.) RiTI0 MICRONN E(L*A-Ba=) 1. 5.0 1.3 0.992 -.004 0.52 2 5.0 0.3 0.900 -.003 0.72 5.• 5.0 0.5 0.987 -.005 0.77 10. 5.0 0.4 0.937 -.005 0.78 15. 5.0 0.4 0.906 -.005 0.81 20. 5.0 0.4 0.936 -.006 0.83 %0. 6.0 0.4 0.91;0 -.004 0.61 4.3. 8.0 0.5 0.935 -.003 0.33 50. 9.9 0.5 0.91,13 -.002 0.18 75. 14.9 0.5 1.0�v.0 -.001 0.04 100. 19.9 0.3 1.0^0 -.000 0.01 150. 29.3 0.1 1.000 -.000 0.00 2-00. 39.3 0.0 1.0;0 -.000 0.00 230. 49.7 0.0 1.C^0 -.000 0.00 .0.1 39.7 0.0 1 . G::3 -.000 0.00 350. 69.6 0.0 1.0010 -.000 0.00 50OMW COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPIED = 2.5 MIS BACKGROUND D V I S U_!L. R4d;,%,3E 50. KM PLUMEM:- VISU'L PLUTT PLUME DOIN'NWIIID OBSEllVE, R. P9;;GE CONTRAST PERCEPT - DISTANCE DISTANCE REDUCTION BLUE -RED AT 0.53 IBILITY ( K ?!) ( I.?I) ( 3) P14TI0 MICRON E(L*A*B*) 1. 3.0 1.2 0.973 -.003 1.04 2. 5.0 0.7 0.9.59 -.010 1.41 5. 5.0 0.4 0.966 -.010 1.51 10. 5.0 0.3 0.91,5 -.010 1.53 15. 5.0 0.3 0.964 -.010 1.59 20. 5.0 0.3 0.9-13 -.010 1.62 50. 6.0 0.3 0.968 - . 009 1. 4.2 40. 8.0 0.4 0.977 -.003 1.08 0. 9.9 0.4 0.9'1 -.00u 0.81 75. 14.9 0.5 0.993 -.00� 0.38 100. 19.9 0.5 0.997 -.002 0.18 150. 29.8 0.7 1.003 -.001 0.04 2G3. 39.E 0.8 1.000 -.000 0.01 2W0. 49.7 0.5 1.000 -.000 0.00 300. 59.7 0.3 1.0^3 -.000 0.00 350. 69.6 0.2 1.000 -.000 0.00 243 506MW COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPEED - 2.5 MIS BACKGROUND VISUAL RANGE = 100. KM PLUDIE- V I SUAL DOUNWIND OBSERVER RANGE DISTANCE DISTANCE REDUCTION 1. 5.0 1.1 2. 5.0 0.6 5. 5.0 0.3 10. 5.0 0.2 15. 5.0 0.2 20. 5.0 0.2 30. •6.0 0 3 40. 8.0 0.3 50. 9.9 0.3 75. 14.9 0.4 103. 19.9 0.4 150. 29.8 0.7 200. 39.8 0.9 250. 49.7 1.1 303. 59.7 1.2 330. 69.6 1.4 50eMw COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPEED = 2.5 MIS BACKGROUND VISU!+.L RAFG'E = 200. 101 PLUE.- VISUAL DOl-,'71 II D, 03SERITIi RANGE D I STANCE D I ST114CE REDUCTION ( KlI) ( MI) ( 7.) 1. 5.0 1.0 2. 5.0 (3.5 5. 5.0 3.3 10. 5.0 ).2 15. 5.0 3.2 20. 5.0 3.2 CO. 6.0 3.2 40. 01.0 0.2 50. 9.9 0.2 75. 14.9 0.3 1C0. 19.9 0.3 130. 29.3 0.6 39.8 0.6 2100. 49.7 1.0 303. 59.7 1.2 3i:0. 69.6 1.4 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY 10,TI0 MICRON E(L*A*B*) 0.903 -.O12 1.34 0.956 -.013 1.78 0.933 -.012 1.90 0.952 -.012 1.93 0.950 -.012 1.99 0.949 -.013 2.04 0.954 -.012 1.86 0.961 -.011 1.60 0.963 -.010 1.35 0.981 -.007 0.85 0.939 -.005 0.54 0.9 :6 - . 003 0.22 0.999 -.002 0.08 1.030 -.001 0.04 1.030 -.0O1 0.02 1.000 -.000 0.02 PLUME PLUME C014TILA-ST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B*) 0.959 -.016 1.58 0.947 -.016 2.05 0.944 -.014 2.17 0.943 -.014 2.20 0.941 -.01ol. 2.27 0.940 -.014 2.32 0.9A3 -.014 2.21 0.950 -.013 1.99 0.956 -.012 1.78 0.969 -.010 1.30 0.979 -.008 0.95 0.939 -.GOG 0.52 0.995 -.O05 0.25 0.997 -.004 0.16 0.9G3 0.12 0.993 -.003 0.11 244 50OMW COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPEED = 5.0 M/S BACKGROWiD VISTJ4 RANGE = 20. KM PLUME- VISUAL PLUME PLUME DOWNWIND OBSERVER RANGE CONTRAST PERCEPT - DISTANCE DISTANCE REDUCTION BLUE -RED AT 0.55 IBILITY (1121) (101) (7.) RAiT10 MICRON E(L*A*B*) 1. 5.0 0.7 0.993 -.003 0.42 2. 5.0 0.5 0.991 -.00c 0.57 5. 5.0 0.3 0.990 -.004 0.58 10. 5.0 0.2 0.992 -.003 0.47 15. 5.0 0.2 0.992 -.003 0.45 20. 5.0 0.2 0.992 -.003 0.44 30. 6.0 0.2 0.995 -.003 0.33 40. 8.0 0.3 0.997 -.002 0.16 50. 9.9 0.3 0.999 -.001 0.10 75. 14.9 0.3 1.000 -.000 0.02 100. 19.9 0.2 1.000 -.000 0.01 150. 29.8 0.1 1.0!�0 -.000 0.00 200. 39.8 0.0 1.010 -.000 0.00 250. 49.7 0.0 1.030 -.000 0.00 300. 59.7 0.0 1.000 -.000 0.00 350. 69.6 0.0 1.000 -.000 0.00 500MW COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPEED = 5.0 MIS BACKGROUND VISUAL RAI GE = 50. 191 PLUIlES- V I SU::L PLT-'Z PLUNEE Dol%lPWI ND OBSElj:tN7_FR R4I; `;E C014 R.4ST PERCEPT - DISTANCE DiST_ECE REDUCTIGIl BLUE -RED AT 0.55 IEILITY ( IQ•1) (ICH) ( No) RATIO Nicit!X; E( L*A'.xB�=) 1. 5.0 0.6 0.932 -.O�G 0.83 2. 5.0 0.4 0.975 -.C.:7 1.11 5. 5.0 0.2 0.974 -.007 1.13 10. 5.0 0.2 0.979 -.0=5 0.92 15. 5.0 0.2 0.901) - . CG:i 0. C7 20. 5.0 0.2 0. 9-0 - . c05 0. C17 30. 6.0 0.2 0.9n�l 0.76 4.0. 8.0 0.2 0.9�3 0012 0.53 50. 9.9 0.2 0.991 -.011:3 0.4•41 75. 14.9 0.3 0.996 2 0.21 100. 19.9 0.3 0.993 -. _=i 0.11 150. 29.3 0.4 1.0130 .OGO 0.02 200. 39.3 0.3 1 . C; 3 - . 0 0. 1 0.01 250. 49.7 0.2 1.G00 -.Ou 0.00 300. 59.7 0.1 1.000 -.4C0 0.00 350. 69.6 0.0 1.000 -.CCU O.CO 245 50OMW COAL-F I PEED PLANT PASQUILL-GIFFSRI) C WIND SPED = 3.0 MIS BACKGROU14D VISUAL RANGE = 100. Kh PLUMM- V I S Li DJI.'NWIFI) CI;SER7,Zii RANGE DISTAIICE DISTANCE REDUCTION (hTD (IQD (9) 1. 5.0 0.6 2. 5.0 0.3 5. 5.0 0.2 10. :..0 0.1 15. 5.0 0.1 20. 5.0 0.1 30. 6.0 0.1 4.0. 8.0 0.2 50. 9.9 0.2 7.3. 14.9 0.2 IGO. 19.9 0.3 150. 29.8 0.4 Coo. 39.8 0.4 250. = 9.7 O . Of 300" . 39.7 0.3 350. 60.6 0.3 50OM4+ COAL-FIRED PLANT PASCUILL-GIFFOIU-) C WI ND SPIED = 5.0 X/S BACKGROURD VISUAL RANCE = 200. ICI PLL'PIE- V I SUAL DOT%71 i I I7D OBSERVER RAIr'GE DISTANCE DISTAIXE REDUCTION ( IOI) ( IG_) (,,IS) 1• 5.0 0.5 2. 5.0 0.3 S. 5.0 0.1 10. 3.0 0.1 13. 5.0 0.1 2,). 5.0 0.1 30. 6.0 0.1 4.0, 8.0 0.1 �0. 9.9 0.1 75. 1C•.9 0.2 l0o. 19.9 0.2 150. 29.8 0.3 203. 39.8 0.3 270. 49.7 0.3 3GO. 59.7 0.3 350. 69.6 0.3 PLUMY PLUME CONTRP_:T PERCEPT - BLUE -RED AT 0.55 1BILITY RATIO MICRON E(L*A*B*) 0.974 -.003 1.06 0.965 -.009 1.40 0.964 -.009 1.42 0.971 -.007 1.15 0.973 -.007 1.09 0.973 -.007 1.09 0.975 -.006 1.00 0.979 -.006 0.86 0.9�,' -.005 0.73 0.990 -.00e'r 0.48 0.994 -.003 0.31 0.993 -.002 0.11 0.999 -.001 0.05 1.003 -.001 0.03 1."0 -.()00 0.01 1.003 -.000 0.01 PLUME PLMM- CONTRAST PERCEPT- P.LUE-REED Ail' 0.55 IBILITY P14 IO MICRON E(L*A*B,::) 0.963 -.011 1.23 0.953 -.011 1.61 0.953 -.010 1.62 0.966 -.003 1.31 0.963 -.001 1.2 0. ;;;,i -. ,%3 1.24 0.970 -.CG7 1.17 0.973 -.007 1.07 0.1976 -.007 0.96 0.9-3 -.006 0.73 0.933 -.003 0.55 0.994 -.003 0.27 0.997 -.003 0.16 0.998 -.00y 0.10 0.999 -.001 0.07 0.9019 -.001 0.05 246 50OMW COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPEED = 2.5 MIS BACKGROUND VISUAL RANGE = 20. KM PLU:IE- VISUAL PLUM PLUME DOWNWIND OBSERGER RANGE CONTRACT PERCEPT - DISTANCE DISTANCE REDUCTICII BLUE -RED AT 0.55 1BILITY (10I) ( K.'ll (7.) RATIO MICRON E(L*A*B*) 1. 5.0 1.6 0.990 -.035 0.63 2. 5.0 1.3 0.937 -.006 0.78 5. 5.0 1.0 0.9"2 -.008 1.10 10. 5.0 0.9 0.978 -.009 1.35 15. 5.0 0.8 0.976 -.010 1.41 20. 5.0 0.8 0.977 -.009 1.39 30. 6.0 0.7 0.985 -.007 0.95 40. 8.0 0.7 0.993 -.004 0.48 50. 9.9 0.7 0.997 -.003 0.23 75. 14.9 0.6 1.030 -.CO1 0.03 100. 19.9 0.3 1.0^0 -.000 0.02 130. 29.8 0.0 1.000 -.000 0.00 200. 39.3 0.0 1.000 -.000 0.00 250. 49.7 0.0 1.0 -.000 0.00 300. 59.7 0.0 1.0f.0 -.000 0.00 350. 69.6 0.0 1.000 -.000 0.00 500MW COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPED = 2.5 M/S BACKGROUND VISUAL RANGGE = 50. KM PLUP)E- VISUAL PLUME PLUME DOWNWIND 0BSERTvT_III RANGE CONTRAST PERCEPT- DISTANCI: DISTANCE REDUCTION BLUE -RED AT 0.55 IBILITY (KP1) (KP1) ( 7.) RAT 10 MICRON E(L*A*B*) 1. 5.0 1.5 0.973 -.010 1.25 2. 5.0 1.2 0.966 -.011 1.55 5. 5.0 0.9 0.952 -.014 2.17 10. 5.0 0.7 0.941 -.017 2.65 15. 5.0 0.6 0.938 -.018 2.78 20. 5.0 0.6 0.939 -.017 2.73 30. 6.0 0.5 0.931 -.014 2.20 40. 8.0 0.5 0.967 -.011 1.57 50. 9.9 0.5 0.977 -.009- 1.14 75. 14.9 0.6 0.990 -.005 0.54 100. 19.9 0.6 0.996 -.003 0.26 150. 29.8 0.7 0.999 -.001 0.07 200. 39.8 0.7 1.000 -.001 0.02 250. 49.7 0.5 1.000 -.000 0.01 300. 59.7 0.2 1.000 -.000 0.00 350. 69.6 0.1 1.000 -.000 0.00 247 50OMW COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPEED - 2.5 MIS BACKGR0UND VISUAL RANGE = 100. KM PLUME- VISUAL PLUME PLUME DOT-14WI14D OBSERX-ER P.45GE CONTRLST PERCEPT - DISTANCE DISTNCE REDUCTION BLUE -RED AT 0.55 IBILITY 021) (IC1) (R) RAT 10 MICRON E(L*A*B*) 1. 5.0 1.3 0.961 -.014 1.61 2. 5.0 1.1 0.952 -.015 1.97 5. 5.0 0.7 0.932 -.019 2.74 10. 5.0 0.6 0.918 -.021 3.34 15. 5.0 0.5 0.914 -.022 3.51 20. 5.0 0.4 0.915 -.022 3.43 30. 6.0 0.4 0.923 -.019 2.93 40. 6.0 0.4 0.944 -.016 2.35 50. 9.9 0.4 0.956 -.014 1.91 75. 14.9 0.4 0.974 -.010 1.20 100. 19.9 0.5 0.984 -.007 0.77 150. 2).8 0.6 0.9t�.4 -.005 0.35 203. 39.8 0.7 0.993 -.003 0.17 250. 49.7 0.9 0.999 -.002 0.08 300. 59.7 1.1 1.0A0 -.001 0.04 350. 69.6 1.5 1.000 -.001 0.02 500MW COAL-FIRED PLANT PASQUILL-G?FFO;� D WIND SPED = 2.5 HIS BACKGROUND VISU_4L RANGE = 200. Y.M PLUME- VISUAL PLUM PLWIE DOIti'Nti IND OI 3r-71 "ZR RA -AGE COIiTRAST PERCEPT - DISTANCE DISTAIiCE REDUCTION BLUE -RED AT 0.53 IBILITY (1121) ( Kell ( ?) P14TI O MICRON E(L*A*B*) 1.. 5.0 1.2 0.951 -.020 1.90 2. 5.0 0.9 0.941 -.020 2.29 5. 5.0 0.6 0.919 -.022 3.15 10. 5.0 0.5 0.902 -.025 3.83 15. 5.0 0.4 0.8^a -.026 4.01 20. 5.0 0.4 0.900 -.025 3.93 30. 6.0 0.3 0.913 -.022 3.44 40. 8.0 0.3 0.927 -.019 2.92 50. 9.9 0.3 0.938 -.017 2.52 75. 14.9 0.3 0.957 -.014 1.83 100. 19.9 0.4 0.970 -.011 1.36 150. 29.8 0.5 0.933 -.009 0.83 200. 39.8 0.6 0.991 -.007 0.52 250. -:-9.7 0.0 0.995 -.005 0.33 3C0. 59.7 1.0 0.997 -.00er 0.20 353. 69.6 1.4 0.993 -.003 0.12 rE- 50OMW COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPEED = 5.0 MIS BACKGROUND VISUAL R4NGE = 20. KM PLWIE- VISU:IL PLUMEE PLUME VD OGSEIRtiER RANICE CONTRacT PERCEPT- DISTAN.E DISTANCE REDUCTION BLUE -RED AT 0.55 IBILITY ( ILI) ( KII) (7.) RATIO MICRON E(L*A-rB*) 1. 5.0 1.2 0.994 -.003 0.37 2. 5.0 0.9 0.991 -.004 0.53 5. 5.0 0.6 0.987 -.005) 0.81 10. 5.0 0.5 0.934 -.006 0.95 15. 5.0 0.5 0.935 -.006 0.91 20. 5.0 0.4 0.936 -.006 0.83 30. 6.0 0.4 0.991 -.004 0.53 40. 8.0 0.4 0.996 -.002 0.26 50. 9.9 0.4 0.91�3 -.001 0.13 75. 14.9 0.3 1.0�0 -.000 0.03 100. 19.9 0.2 1.fl0 -.000 0.01 150. 29.8 () . O 1.0130 -.COO 0.00 200. 39.8 0.0 1.0^3 -.000 0.00 250. 49.7 0.0 1.000 -.000 0.00 300. 59.7 0.0 1.0'i -.00O 0.00 350. 69.6 0.0 1.030 -.000 0.00 500MW COAL. -FIRED PLANT PASQUILL-GIFFORD D WIND SPEED = 5.0 NIS BACKGROURD VISUAL RAI GE = 50. YJI PLmm_ VISUAL PLUP''- PLUME DOWNWIND OBSERVER RANGE CONTRAST PERCEPT - DISTANCE DISTAI.CE REDUCTION BLUE -RED AT 0.55 IBILITY (101) (101) ( 17) RAT 10 MICRON E(L*A*B*) 1. 5.0 1.1 0.934 -.006 0.74 2. 5.0 0.6 0.977 -.007 1.04 5. 5.0 0.5 0.964 -.010 1.59 10. 5.0 0.4 0.933 -.012 1.95 15. 5.0 0.3 0.960 -.011 1.78 20. 5.0 0.3 0.963 -.010 1.63 30. 6.0 0.3 0.973 -.000 1.23 40. 8.0 0.3 0.922 -.006 0.84 50. 9.9 0.3 0.9E3 -.005 0.59 75. 14.9 0.3 0.995 -.003 0.26 103. 19.9 0.3 0.993 -.002 0.12 150. 29.8 0.4 1.O00 -.001 0.03 200. 39.8 0.4 1.000 -.000 0.01 250. 49.7 0.2 1.O00 -.000 0.00 300. 59.7 0.1 1.O00 -.00O 0.00 3150. 69.6 0.0 1.0100 -.000 0.00 249 50OMW COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPEED = 5.0 M/S BACKGROUND VISUAL RANGE = 100. KM PLUME- VISUAL DOTTNWIND OBSERVER RAY GE DISTANCE DISTANCE REDUCTION HID 07.) 1. 5.0 1.1 2. 5.0 0.7 5. 5.0 0.4 10. 5.0 0.3 15. 5.0 0.3 20. 5.0 0.2 30. 6.0 0.2 40. 8.0 0.2 50. 9.9 0.2 75. 14.9 0.2 100. 19.9 0.3 150. 29.6 0.4 2GD. 39.8 0.4 250. 49.7 0.4 300. 59.7 0.3 350. 69.6 0.3 50OMW COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPED = 5.0 M/S BACKGROUND VISUAL RANGE = 200. 101 PLUMM- V I S U.AL DOWNWIND OBSERVER RAN GE DISTANCE DISTANCE REDUCTION ( I 1) ( ILI) (R) 1. 5.0 1.0 2. 5.0 0.6 5. 5.0 0.4 10. 5.0 0.3 15. 5.0 0.2 20. 5.0 0.2 GO. 6.0 0.2 40. 8.0 0.2 50. 9.9 0.2 75. 14.9 0.2 103. 19.9 0.2 ISO. 29.6 0.3 ?03. se). 8 0.3 230. 49.7 0.3 303. 59.7 0.3 350. 69.6 0.3 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICROTti E(L*A*B*) 0.977 -.010 0.97 0.967 -.010 1.33 0.950 -.013 2.00 0.912 -.015 2.33 0.944 -.014 2.23 0.949 -.013 2.05 0.960 -.010 1.63 0.970 -.008 1.25 0.977 -.007 0.98 0.987 -.005 0.36 0.993 -.003 0.36 0.99a -.002 0.13 0.999 -.001 0.05 1.000 -.001 0.03 1.000 -.000 0.01 1.000 -.000 0.01 PLUME PLUME COTvTR9ST PERCEPT - BLUE -RED AT 0.55 IBILITY RkTIO MICRON E(L*A*B*) 0.970 -.014 1.16 0.960 -.013 1.54 0.941 -.016 2.29 0.931 -.017 2.66 0.934 -.016 2.55 0.919 -.014• 2.34 0.951 -.012 1.91 0.961 -.010 1.55 0.963 -.009 1.29 0.979 -.007 0.88 0.986 -.00; 0.63 0.993 -.004 0.32 0.997 -.003 0.17 0.993 -.002 0.11 0.999 -.001 0.07 0.999 -.001 0.05 250 500MW COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 2.5 PINS BACKGROUND VISUAL RP.FGE 20. n-t PLUlf - V I SUP-L PLUM PLUM DOI•'NWIND OI;SFP<1."ER R IME CO`;TRkST PERCEPT - DISTANCE DISTANEE REDUCTION BLL-1-r-RED AT 0.53 IBILI7Y IC( 11) M RkT10 PiIcFIGN E(L 4-=B%.,) 1. 5.0 2.9 0.939 -.01OG 0.74 2. 5.0 2.2 0.937 -.0O3 0.35 5. 5.0 1.5 9.931 -.;Gw 1.14 10. 5.0 1.3 0.976 -.010 1.47 15. 5.0 1.2 0.972 -.012 1.67 20. 5.0 1.2 0.9 00 -.012 1.30 30. 6.0 1.2 0.977 -.011 1.4.5 40. 8.0 1.3 0.903 0.31 50. 9.9 1.3 0.991' - . C 3 0. 4 75. 14.9 1.2 0.999 -.0O2 0.10 100. 19.9 0.6 1.003 -.001 0.03 150. 29.3 0.0 1 . C;,0 -, CGO 0.00 2CO. 39.8 0.0 L OCO -.0 0.GO 230. 49.7 0.0 1.0113 -.G,.O 0.00 300. 59.7 0.0 1,0^0 -.GGO 0.G0 350. 69.6 0.0 1.000 -.OGO 0.00 5001fW COAL-FIRED PLANT PASOJILL-GIFFORD E WIND SPEED = 2.5 111S BACICGROUT+D VISUAL IL.4 4CE = 50. KM PLUM- V I S ITA IL PLUM PLWIE DOI-1114 'I ND OESER7VER R" ''GE CONTRAST PERCEPT - DISTANCE DISTANCE REDI CTION BLUE -RED AT 0.55 IBILITY ( I41) ( K[1) ( ) RAT 10 PI I CROR 1. 5.0 2.7 0.959 -.013 1.50 2 5.0 2.0 0.954 -.014 1.70 5. 5.0 1.3 (.11.930 -.016 2.26 I0. 5.0 1.1 0.936 -.019 2.90 13. 5.0 1.0 0.927 -.021 3.30 20. 5.0 0.9 0.921 -.023 3.56 30. 6.0 ).9 0.927 -.023 3.38 40. 3.0 ).9 0.90 -.020 2.64 50. 9.9 1.0 0.960 -.016 2.01 75. 14.9 1.1 0.n'2 -.010 0.93 100. 19.9 1.1 0.993 -.COS 0.47 ISO. 29.3 1.2 0.999 -.0O2 0.13 200. 39.3 1.3 1.000 -.CO1 0.04 2513. 49.7 0.7 1 . C,03 -.000 0.02 300. 59.7 0.2 1.012,13 -.000 0.01 350. 69.6 0.0 1.011.10 -.000 0.00 251 500MV COAL-FIRED PLANT PASOUILL-GIFFORD E WIND SPEED = 2.5 P"✓S BACKGROUI:D VISUAL RAPiGE = 100. KM PLUn, '- VISUAL PLUME PLUME DoV71WIND OBSL'R�T:,R R.?2iGE COITR-AST PERCEPT- DISTAINCE DIST.0CE REDUCTION BLUE -RED AT 0.55 IBILITY ( I0=) (KH) ( %) RAT10 MICRON E(L*A*B•:,) 1. 5.0 2.5 0.954 -.020 1.97 2 5.0 1.8 0.953 -.019 2.19 5. 5.0 1.2 0.930 -.021 2.E8 10. 5.0 0.9 0.910 -.025 3.63 15. 5.0 0.8 0.893 -.027 4.17 20. 5.0 0.8 0.890 -.029 4.50 30. 6.0 0.7 0.892 -.034 4.52 40. 8.0 0.7 0.907 -.027 3.97 50. 9.9 0.3 0.922 -.025 3.39 75 • 14.9 0.3 0.9;;3 -. 019 2.20 103. 19.9 0.9 0. () :'2 - . 014 1.40 133. 29.3 1.1 0.9^•0 -.0�03 0.62 200. 233. 39.a 49.7 1.2 0.9';G -.CCS 0.29 300, 59.7 1.3 1.5 0.9;9 1.0:,0 -.C43 -.Q02 0.16 350. 69.6 1.8 1.0110 -.001 0.03 0.03 50011W COA_,-FIRED PLAIT PASCUILL-GIFFORD E WIND SPE7_D = 2.5 HIS BACL'GROu cc VISUAL, R..UI (',E = 203. KM DOItNWIND PLUP2:- OrSERV"ER V 15 SAL R- :GE PLUIZ PLUMES DISTAI+CE DISTAl;CE RETDL':TION BLLTE-IzrD CONTRAST AT 0.55 PERCEPT- IBILITY I3Z) ( "=) RIT10 PIICRON E(L*A•:'8•:,) • • 5.0 2.2 0.9=o -.030 2.33 • 5.0 5.0 1.6 0.933 -.027 2.59 1 . 1 0.8 0.914 0.39111 - 27 .... 1=�. 2•,). 5.0 0.7 0.879 -.CEO -.032 �:..23 �� 4.79 5.0 6.0 0.6 0.870 -.034 5.16 ,CO. 3.0 0.6 0.6 0.8G7 -.035 5.32 50. 9.9 0.6 0.379 0.8912 -.033 4.9G I73. 3. 14.9 0.6 0.p22 -.031 -.026 4.50 3.37 150. 19.9 29.3 0.7 0.9:G -.C21 23. 39.3 0.9 0.971 -.016 1,(_G '9.7 i.'.> 0.9u4 -.0I2 0.93 3C�. 59.7 1.2 1.3 0.990 -.010 0.61 330• 69.6 1.7 0.9:4 .. 0.4C 0.997 -.006 0.2G 252 500MW COAL-FIPXD PLANT PASQUILL-GIFFORD E FUND SPEED = 5.0 MIS BACI{GROUND VISUAL RANGE = 20. 121 PLUIf'- VISUAL PLUME PLUME DOls7WIND OBSERXTER R-,NGE CONTRAST PERCEPT - DISTANCE DISTANCE REDUCTION BLUE-P.ED AT 0.55 IBILITY 00-I) ( I`?i) l7.) RAT 10 MICRON E( LTA*B*) 1. 5.0 1.7 0.994 -.003 0.42 2. 5.0 1.2 0.992 -.004• 0.52 5. 5.0 0.9 0.9c'7 -.006 0.81 10. 5.0 0.7 0.9C2 -.007 1.06 15. 5.0 0.7 0.9110 -.00u 1.18 20 5.0 0.7 0.9C0 -.0c3 1.23 30. 6.0 0.7 0.900 -.G07 0.91 -0. 8.0 0.7 0.993 -.004 0.48 50. 9.9 0.7 0.997 -.003 0.25 75. 14.9 0.7 1.000 -.041 0.06 100. 19.9 0.3 1.0^0 -.00O 0.01 150. 29.6 0.0 1.0^0 -.000 0.00 2.00. 39.8 0.0 1.003 -.000 0.00 C50. 49.7 0.0 1.010 -.CG3 0.00 300. 59.7 0.0 1.010 -.Oc0 0.00 350. 69.6 0.0 1.01 -.000 0.00 500NW COAL-FIRED PLANT PASQUILL-GIFFORD E FUND SPEED = 5.0 NIS BACKGROUP-it V1SU -L XL4NGE = 50. KM PLU";✓'- VISUAL PLUMEE PLUME DOUNWIFD OESER"TER P1'--CE CONTRAST PERCEPT - DISTANCE DISTANCE REDUCTION BLUE -RED e1T 0.55 IBILITY (I3-1) ( 0-1) ( 1-1) RAT 10 MICRON E(L*A*B* ) 1. 5.0 1.6 0.982 -.003 0.86 2. 5.0 1.1 0.977 -.000 1.04 5. 5.0 0.7 0.966 -.011 1.59 10. 5.0 C.6 0.9_53 -.013 2.08 15. 5.0 0.5 0.5 3 -.015 2.33 20. 5.0 G.5 0.9=G -.015 2.41 2;0. 6.0 0.5 0.95 -.014 2.10 40. 8.0 0.5 0.967 -.011 1.56 50. 9.9 0.5 0.9 77 -.009 1.15 75. 14.9 0.6 0.990 -.005 0.54 1C0. 19.9 0.6 0.996 -.003 0.26 150. 29.8 0.6 0.999 -.001 0.06 207. 39.8 0.6 1.000 -.000 0.02 2C0. 49.7 0.3 1.0^0 -.O10 0.01 303. 59.7 0.1 1. F - .010 0.00 330. 69.6 0.0 1.000 -.CCO 0.00 253 50OMW COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 5.0 M/S BACKGROUND VISUAL. RANGE = 100. KM PLUME- VISUAL PLUME PLUME DOWNWIND OBSERVER RANGE CONTRAST PERCEPT - DISTANCE DISTANCE REDUCTION BLUE -RED -AT 0.55 IBILITY (KH) (KP1) ( 7.) RATIO MICRON E(L*A*B*) 1. 5.0 1.5 0.974 -.012 1.13 2. 5.0 1.0 0.968 -.012 1.33 5. 5.0 0.6 0.950 -.014 2.01 10. 5.0 0.5 0.935 -.017 2.63 15. 5.0 0.4 0.926 -.019 2.93 20. 5.0 0.4 0.925 -.019 3.04 30. 6.0 0.4 0.932 -.018 2.80 40. 8.0 0.4 0.945 -.016 2.32 50. 9.9 0.4 0.955 -.014 1.92 75. 14.9 0.4 0.974 -.010 1.20 100. 19.9 0.5 0.9(5 -.007 0.76 150. 29.8 0.5 0.995 - . fi0 0.30 200. 39.8 0.5 0.998 -.032 0.13 250. 49.7 0.6 1.O00 -.001 0.05 300. 59.7 0.5 1.000 -.001 0.03 350. 69.6 0.5 1.000 -.000 0.01 50011W COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 5.0 MIS BACKGROUND VISUAL R,.NGE = 200. KM PLUPIE- V I SU_AL PLUME PLUME DOWNti I ND OBSERVER RAIr'CE CONTRAST PERCEPT - DISTANCE DISTANCE REDUCTION BLUE -RED AT 0.53 IBILITY (101) (KIll (Y.) RATIO MICRON E(L*A*B*) 1. 5.0 1.4 0.965 -.018 1.37 2. 5.0 0.9 0.959 -.016 1.57 5. 5.0 0.6 0.940 -.017 2.31 10. 5.0 0.4 0.922 -.020 3.01 15. 5.0 0.4 0.914 -.021 3.35 20. 5.0 0.3 0.911 -.022 3.47 30, 6.0 0.3 0.916 -.021 3.29 40. 8.0 0.3 0.923 -.019 2.89 50. 9.9 0.3 0.938 -.017 2.53 75. 14.9 0.3 0.957 -.014 1.83 100. 19.9 0.4 0.970 -.011 1.33 150. 29.8 0.4 0.986 -.008 0.71 200. 39.6 0.5 0.993 -.005 0.39 230. 49.7 0.5 0.997 -.003 0.21 'AGO. 59.7 0.5 0.996 -.002 0.12 350. 69.6 0.5 0.999 -.002 0.08 254 500MW COAL-FIRED PLANT PASQUILL-CIFFORD F KIND SPEED = 2.5 MIS BACKGROUND VISUAL RANGE ' KM VISUAL PLUME PLUME D0WNWIND OBSERVER RANGE CONTRAST PERCEPT - DISTANCE DISTAIiCE REDUCTION BLUE -RED AT 0.55 IBILJTY ( IM) ( N.) RA a IO MICRON E(L*A*B*) 1. 5.0 3.9 0.986 -.008 0.94 2. 5.0 3.1 0.933 -.009 1.10 5. 5.0 2.4 0.979 -.010 1.35 10. 3.0 2.0 0.974 -.012 1.62 15. 3.0 1.8 0.970 -.013 1.83 20. 5.0 1.8 0.967 -.014� 1.99 30. 6.0 1.8 0.974 -.013 1.68 40. 0.0 1.9 0.936 -.010 1.00 50. 9.9 2.0 0.993 -.007 0.59 75. 14.9 2.2 0.999 -.003 0.16 100.1 19.9 1.1 1.0�0 -.601 0.05 150. 29.8 0.3 1.000 -.000 0.01 200. 39.8 0.0 LOCO -.00C 0.00 250. 49.7 0.0 1.030 -.000 0.00 300. 59.7 0.0 1.000 -.E00 0.00 350. 69.6 0.0 1.000 -.000 0.00 500MW COAL-FIRED PLANT PASQUILL-GIFFOFJ) F WIND SPEED = 2.5 M/S BACKGROUND VISUAL RyIIGE = 50. KM PLUiry- V I SU AL PLUPT PLUME DOWNWIND 083ERV E. R FUL E COIITILAcT PERCEPT - DISTANCE DISTAPCE REDUCTION BLUE-RZD AT 0.55 IBILITY ( ICI) ( KPI) ( 7.) RATIO MICRON E(L*A*B*) 1. 5.0 3.6 0.961 -.018 1.92 2 5.0 2.9 0.953 -.016 2.21 5. 5.0 2.1 0.942 -.020 2.68 10. 5.0 1.7 0.930 -.023 3.21 1G. 5.0 1.5 0.920 -.025 3.62 20. 5.0 1.5 0.913 -.026 3.96 30. 6.0 1.4 0.915 r 3.94 S-^. 8.0 1.5 0.932 -.025 3.31 30. 9.9 1.6 0.946 -.023 2.71 75. 14.9 1.8 0.973 -.017 1.56 100. 19.9 2.0 0.907 -.012 0.87 1�;0. 29.8 2.2 0.993 -.005 0.28 39.3 2.3 1.000 -.002 0.10 25C. 49.7 1.2 1.030 -.001 0.05 Goo. 59.7 0.1 1.030 -.000 0.02 330. 69.6 0.0 1.000 -.000 0.01 255 500MW COAL-FIRED PLANT PASQUILL-GIFFORD F WIRD SPEED = 2.5 111S BACKGROUND V1SUr.L RANGE = 100. KM rpm- VISUAL DOVINWIRD OBSERVER RANGE DISTANCE DISTANCE REDUCTION 1. 5.0 3.4 2 5.0 2.7 5. 5.0 1.9 10. 5.0 1.5 15. 5.0 1.3 20. 5.0 1.3 00. 6.0 1.2 40. 8.0 1.2 50. 9.9 1.3 75. 14.9 1.4 100. 19.9 1.6 150. 29.8 1.9 200. 39.8 2.1 250. 49.7 2.3 300. 59.7 2.5 350. 69.6 2.8 500NW COAL-FIRED PLANT PASQUILL-GIFFORD F WIND SPEED = 2.5 N,/S BACKGROUOD VISUAL RANGE = 200. KM PLUP-- VISUAL DOWNWIND OBSERVER RAJ;GE DISTANCE DISTANCE REDUCTION (01) (I21) ( IND 1. 5.0 3.1 2. 5.0 2.4 5. 5.0 1.7 10. 5.0 1.3 10. 5.0 1.2 20. 5.0 1.1 J. 6.0 1.0 40. 3.0 1.0 50. 9.9 1.0 75. 14.9 1.1 100. 19.9 1.2 150. 29.8 1.5 2C0. 39.3 1.7 250. 49.7 1.9 3.,0. 59.7 2.1 350. 69.6 2.5 PLLTfE PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICFloN E(L*A*B*) '0.942 -.027 2.53 0.932 -.026 2.86 0.917 -.027 3.43 0.901 -.029 4.08 0.889 -.032 4.60 0.879 -.034 5.02 0.874 -.036 5.30 0.815 -.036 4.99 0.897 -.035 4.59 0.926 -.031 3.51 0.950 -.026 2.57 0.973 -.01a 1.32 0.9;1 -.012 0.69 0.997 -.00; 0.38 0.999 -.005 0.22 1.0010 -.003 0.14 PLUME PLUME CORTILAST PERCEPT - BLUE -RED AT 0.55 IBILITY FLAT 10 MICRON E(L*A*B*) 0.923 -.039 3.06 0.913 -.036 3.40 0.893 -.035 4.00 0.830 -.036 4.72 0.866 -.039 5.31 0.853 -.G41 5.78 0.845 -.043 6.27 0.849 -.044 6.27 0.855 -.045 6.12 0.873 -.043 5.41 0.902 -.040 4.58 0.940 -.033 3.12 0.964 -.027 2.11 0.978 -.022 1.45 0.937 -.010 1.01 0.992 -.015 0.72 256 500MW COAL-FIRED PLANT PASQUILL-GIFFORD F WIND S?EED = 5.0 M/S BACKGROUND VISUAL RANGE = 20. KM PLUME- VISUAL PLUME PLUME DOI-,'NW I 14D OBSERVER RANGE CONTRAST PERCEPT- DISTAI,'CE DISTANCE REDUCTION BLUE -RED AT 0.55 IBILITY (KM) (KID (7.) RATIO MICRON E(L*A*BW) 1. 3.0 2.3 0.993 -.004 0.47 2. 5.0 1.7 0.992 -.004 0.54 5. 5.0 1.2 0.988 -.005 0.76 10. 5.0 1.1 0.9&3 -.007 1.03 15. 5.0 1.0 0.9G0 -.008 1.21 20. 5.0 1.0 0.978 -.009 1.35 30. 6.e 1.0 0.982 -.009 1.15 40. 8.0 1.1 0.990 -.006 0.68 50. 9.9 1.1 0.995 -.004 0.39 75. 14.9 1.2 0.999 -.002 0.10 100. 19.9 0.6 1.030 -.001 0.03 150. 29.8 0.0 1.033 -.000 0.00 200. 39.8 0.0 1.Ov0 -.000 0.00 250. 49.7 0.0 1.000 -.000 0.00 300. 59.7 0.0 1.000 -.000 0.00 350. 69.6 0.0 1.000 -.000 0.00 506MV COAL-FIRED PLANT PP_SQU ILL-GIFFO_RD F WIND SPEED = 5.0 MIS BACKGROUND VISUAL RANGE = 50. KM PLUMEM- VISUAL PLUME PLUME DOWNWIND OBSERVER RANGE CONTRAST PERCEPT- DISTAIWCE DISTANCE REDUCTION BLUE -RED AT 0.55 IBILITY (421) ( KI.1) (9) RAT 10 MICRON E(L*A*B*) 1. 5.0 2.1 0.981 -.009 0.97 2. 5.0 1.6 0.977 -.009 1.09 5. 5.0 1.1 0.967 -.011 1.50 10. 5.0 0.9 0.955 -.014 2.03 15. 5.0 0.8 0.947 -.016 2.39 20. 5.0 0.3 0.941 -.017 2.66 30. F�.0 0.6 0.942 -.018 2.67 40. 8.0 0.8 0.953 -.016 2.22 50. 9.9 0.9 0.964 -.014 1.76 73. 14.9 1.0 0.983 -.010 0.97 100. 19.9 1.1 0.992 -.007 0.52 150. 29.6 1.2 0.999 -.003 0.15 200. 39.8 1.2 1.000 -.001 0.05 250. 49.7 0.6 1.0:0 -.001 0.02 300. 59.7 0.0 1.000 -.000 0.01 350. 69.6 0.0 1.000 -.000 0.01 257 500MW COAL-FIRED PLANT PASQUILL-GIFFORD F WI1\D SPEED = 5.0 MIS BACKGROUND VISUAL RANGE = 100. KM PLUME- VISUAL DOWNWIND OBSERVER RANGE DISTANCE DISTANCE REDUCTION ( ICI) ( KM) ( :) 1. 5.0 2.0 2. 5.0 1.5 5. 5.0 1.0 10. 5.0 0.8 15. 5.0 0.7 20. 5.0 0.7 30. 6.0 0.6 40. 8.0 0.7 50. 9.9 0.7 75. 14.9 0.8 100. 19.9 0.9 150. 29.8 1.0 200. 39.8 1.1 250. 49.7 1.1 300. 59.7 1.2 350. 69.6 1.2 500MW COAL-FIRED PLANT PASQUILL-GIFFORD F WIND SPEED = 5.0 NIS II?iCKGROUND VISUAL RANGE = 200. KM PLUDIE- V i SU__liL DOWNWIND OBSERVER R4NGE DISTANCE DISTANCE REDUCTION ( ICll (la-D ( 9.) 1. 5.0 1.6 2. 5.0 1.3 5. 5.0 0.9 10. 5.0 0.7 15. 5.0 0.6 20. 5.0 0.6 30. 6.0 0.5 40. 8.0 0.5 50. 9.9 0.5 75. 14.9 0.6 100. 19.9 0.6 150. 29.8 0.3 200. 39.8 0.9 230. 49.7 1.0 300. 59.7 1.0 350. 69.6 1.1 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY KATIO MICRON E(L*A*B*) 0.971 -.015 1.28 0.966 -.014 1.41 0.953 -.015 1.91 0.937 -.0113 2.57 0.926 -.020 3.02 0.918 -.022 3.35 0.914 -.024 3.57 0.922 -.023 3.32 0.931 -.022 2.99 0.953 -.018 2.17 0.970 -.015 1.53 0.908 -.010 0.75 0.993 -.036 0.37 0.998 -.004 0.20 0.999 -.003 0.11 1.000 -.002 0.07 PLUME PLUME CONTRAST PERCEPT- BLUE-RZD AT 0.55 IBILITY RATIO MICRON E(L*A*B*) 0.960 -.022 1.56 0.957 -.019 1.69 0.9i3 -.019 2.21 0.924 -.022 2.95 0.911 -.024 3.46 0.902 -.026 3.84 0.894 -.023 4.21 0.898 -.028 4.15 0.904 -.028 3.96 0.924 -.025 3.32 0.941 -.023 2.70 0.965 -.018 1.75 0.980 -.014 1.14 0.988 -.011 0.73 0.993 -.009 0.51 0.996 -.007 0.36 258 1000MW COAL-FIRED PLANT pASQUILL-GIFFORD C WIND SPEED = 2.5 MIS BACKGROUND VISUAL RANGE = 20. KM PLILITIE- VISUAL PLUME PLUME DOWNW I IiD OE_ ER :ER RAPS GE CONTILe.ST PERCEPT- DIST"1iCE DISTANCE REDUCTION BLUE -RED AT 0.55 IBILITY 401) ( KZ1) ( PSI) RATIO MICRON E(L*A*B*) 1. 5.0 2.4 0.990 -.005 0.66 2. 5.0 1.5 0.986 -.006 0.66 5. 5.0 0.8 0.905 -.006 0.94 10. 5.0 0.7 0.961 -.003 1.12 15. 5.0 0.7 0.970 -.009 1.33 20. 5.0 0.3 0.976 -.010 1.45 30. 6.0 0.8 0.982 -.00E 1.12 40. 8.0 0.9 0.991 -.006 0.62 50. 9.9 0.9 0.996 -.004 0.34 75. 14.9 0.8 0.999 -.001 0.08 100. 19.9 0.5 1.000 -.000 0.02 150. 29.8 0.2 1.000 -.000 0.00 200. 39.8 0.1 1.000 -.000 0.00 250. 49.7 0.0 1.000 -.000 0.00 300. 59.7 0.0 1.000 -.000 0.00 350. 69.6 0.0 1.0000 -.003 0.00 1000MW COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPEED = 2.5 M/S BACKGROUND VISUAL RAITGE = 50. KM PLUPa-;- VISUAL PLUMEE PLUME DOU71WI ND OBSERVER RANGE CONTRA T PERCEPT - DISTANCE DISTAFCE REDUCTION BLUE -RED AT 0.55 IBILITY (I21) (lei) ( R) RATIO MICRON E(L*A*B*) 1. 5.0 2.3 0.973 -.012 1.32 2. 5.0 1.3 0.963 -.012 1.71 5. 5.0 0.7 0.959 -.012 1.84 10. 5.0 0.5 0.950 -.014 2.21 15. 3.0 0.5 0.941 -.017 2.61 20. 5.0 0.6 0.936 -.018 2.66 30. 6.0 0.6 0.943 -.017 2.60 40. 8.0 0.7 0.957 -.015 2.03 50. 9.9 0.7 0.969 -.012 1.55 75. 14.9 0.8 0.986 -.003 0.77 100. 19.9 0.9 0.994 -.005 0.36 150. 29.8 1.1 0.999 -.002 0.11 203. 39.8 1.0 1.000 -.001 0.04 2%:3. 49.7 0.7 1.000 -.000 0.02 301). 59.7 0.5 1.01,10 -.OGO 0.01 350. 69.6 0.3 1.('00 -.000 0.00 259 100071W COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPEED = 2.5 MIS BACKGROUND VISUAL RANCE = 100. KM PLUME- VISUAL DOWNWIND OBSERILR RANGE DISTANCE DISTANCE REDUCTION 1. 5.0 2.1 2. 5.0 1.2 5. 5.0 0.6 10. 5.0 0.4 15. 5.0 0.4 20. 5.0 0.4 30. 6.0 0.5 40. 8.0 0.5 50. 9.9 0.6 75. 14.9 0.7 100. 19.9 0.7 150. 29.8 1.0 200. 39.8 1.2 230. 49.7 1.4 300. 39.7 1.7 350. 69.6 2.2 1000MW COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPEED = 2.5 MIS BACKGROU?iD V 1 SUAL RANGE = 201. KM PLUilE- VISUAL DOWNWIND OBSERVER R4I'GE DISTANCE DISTANCE REDUCTION (I2-1) (lei) ( 7 ) 1. 5.0 1.9 2. 3.0 1.1 5. 5.© 0.5 10. 5.0 0.4 15. 5.0 0.4 20. 5.0 0.4 30. 6.0 0.4 4-0. 3.0 0.4 50. 9.9 0.4 75. 14.9 0.5 100. 19.9 0.6 150. 29.8 0.8 200. 39.13 1.0 250. 49.7 1.2 300. 59.7 1.6 350. 69.6 2.2 PLUn PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B*) 0.960 -.018 1.73 0.947 -.017 2.16 0.942 -.016 2.32 0.931 -.018 2.78 0.919 -.021 3.29 0.911 -.022 3.60 0.916 -.022 3.47 0.928 -.021 3.04 0.940 -.019 2.61 0.963 -.014 1.72 0.977 -.011 1.12 0.991 -.00", 0.53 0.997 -.004 0.26 0.999 -.003 0.13 1.000 -.0012 0.07 1.000 -.001 0.04 PLUNZE PLUIZE CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY PATIO MICRON E(L*A*-Bx,) 0.947 -.026 2.09 0.934 -.022 2.54 0.931 -.019 2.66 0.916 -.021 3.18 0.904 -.024 3.76 0.895 -.026 4.11 0.897 -.026 4.08 0.906 -.025 3.70 0.916 -.024 3.45 0.939 -.020 2.63 0.956 -.017 1.99 0.975 -.014 1.25 0.986 -.011 0.80 0.992 -.009 0.52 0.995 -.007 0.32 0.997 -.O05 0.21 o 1000MW COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPEED = 5.0 MIS BACKGROUND VISUAL RANGE = 20:-IM PLUPM- V I SUM. PLUM PLUME DON,'I WIND OP.SE?VER R4,]1GE CONTR&ST PERCEPT - DISTANCE•' DISTAI:CE REDUCTION BLUE -RED AT 0.55 IBILITY (I21) ( I{Ii) ( S:) RATIO MICRON E(L*A*,B*) 1. 5.0 1.3 0.992 -.001 0.50 2 5.0 0.13 0.939 -.005 0.70 5. 5.0 0.5 0.9�5 -.006 0.86 10. 5.0 0.4 0.9v6 -.006 0.84 15. 5.0 0.4 0.94,116 -.006 0.83 20. 5.0 0.4 0.986 -.006 0.85 30. 6.0 0.4 0.990 -.005 0.64 40. 8.0 0.5 0.995 -.003 0.35 50. 9.9 0.5 0.993 -.002 0.19 75. 14.9 0.5 1.000 -.001 0.05 100. 19.9 0.3 1.630 -.000 0.01 150. 29.8 0.1 1.000 -.000' 0.00 200. 39.8 0.0 1.0110 -.OGO 0.00 2710. 49.7 0.0 I.OvO -.000 0.00 300. 59.7 0.0 1.0^0 -.010 0.00 350. 69.6 0.0 1. 0 ;0 -.GOO 0.00 1004MW COAL-FIRED PLANT FASQUILL-GIFFO."M C FIND SPEE5 = 5.0 M%S EACYCRQUIiD VISUAL FLINGE = 50. I01 FLUi'Mv- V I SUAL PLUME PLUIIC DO?T1WIND OBSERVER RANGE CONTRAST PERCEPT- DI;;Tr?NCE DISTANCE REDUCTION BLUE -RED AT 0.55 IBILITY I ►•1) ( :) P14TI0 HICRON E(L*A*B*) 1. 5.0 1.2 0.979 -.00R 0.99 2. 5.0 0.7 0.969 -.009 1.37 5. 5.0 0.4 0.961 -.011 1.73 10. 5.0 0.3 0.963 -.010 1.64 15. 5.0 0.3 0.963 -.010 1.62 20. 5.0 0.3 0.962 -.010 1.66 30. 6.0 0.3 0.967 -.010 1.47 ,CO. 8.0 0.4 0.976 -.003 1.14 50. 9.9 0.4 0.932 -.007 0.813 75. 1:.9 0.5 0.992 -.GG4 0.45 140. 19.9 0.5 0.9116 -.003 0.23 130. 29.3 0.6 0.911%9 -.001 0.06 200. 391.£3 0.5 1.E03 -.003 0.02 ...,3. `9.7 0.4 1. ©\ 0 .OGO 0.01 \,00. 59.7 0.2 1.0..0 .000 0.00 350. 69.6 0.1 1.000 -.OuO 0.00 261 100014W COAL-FIRED PLANT PASQUILL-GIFFO_RD C WIND SPED = 5.0 MIS BACKGROUND VISUAL R_0GE = 100. KM PLU17-- VISUAL. DOWNWIND OESEBATER RAIIGE DISTANCE DISTANCE REDUCTION I31) (10D ('%) 1. 5.0 1.1 2. 5.0 0.6 5. 5.0 0.3 10. 5.0 0.2 15. 5.0 0.2 20. 5.0 0.2 30. 6.0 0.2 40. 8.0 0.3 50. 9.9 0.3 75. 14.9 0.4 1C0. 19.9 0.4 150. 29.8 0.5 200. 39.3 0.6 250. 49.7 0.7 300. 59.7 0.7 350. 69.6 0.6 1000MW COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPEED = 5.0 MIS BACKGROUND VISUAL RARGE = 200. KM PLTJI-y- V I SU L DON71WIIdD GR3E:.�' R RANGE DISTANCE DISTANCE REDUCTION ( Icri) ( 101) ( R ) 1. 5.0 1.0 2 5.0 0.6 5. 5.0 0.3 10. 5.0 0.2 15_ 5.0 0.2 20. 5.0 0.2 10. 6.0 0.2 40. 3.0 0.2 5G. 9.9 0.2 75. 14.9 0.3 100. 19.9 0.3 150. 29.8 0.5 200. 39.3 0.5 250. 49.7 0.6 300. 39.7 0.6 350. 69.6 0.6 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY PATIO MICRON E(L*A*Bw) 0.969 -.012 1.28 0.957 -.012 1.73 0.946 -.014 2.18 0.943 -.013 2.06 0.949 -.013 2.04 0.943 -.013 2.08 0.952 -.012 1.95 0.959 -.011 1.70 0.966 -.010 1.46 0.976 -.005 0.99 0.987 -.006 0.67 0.995 -.004 0.29 0.998 -.002 0.12 1.01,10 -.001 0.05 1.000 -.001 0.03 1.000 -.000 0.02 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RkTIO MICRON E(L*A*B*) 0.961 -.016 1.51 0.943 -.015 2.00 0.935 -.016 2.49 0.939 -.015 2.35 0.940 -.014 2.32 0.939 -.015 2.37 0.941 -.014 2.29 0.947 -.014 2.11 0.952 -.013 1.93 0.964 -.011 1.51 0.974 -.010 1.18 0.986 -.007 0.68 0.993 -.G35 0.39 0.996 -.004 0.22 0.993 -.003 0.14 0.999 -.002 0.10 262 100oMW COAL-FIRED PLANT pASQUILL-GIrFORD D WIND SPEED = 2.5 M/S BACKGROUND VISUAL RAN(E PLUME - DOWNWIND OBSERVER DISTANCE DISTANCE ( Ial) (I21) 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 cr0. 8.0 50. 9.9 75. 14.9 100. 19.9 150. 29.8 200. 39.8 250. 49.7 300. 59.7 350. 69.6 1000MW COAL-FIRED PLANT PASQUILL-GIFFOP.D D WIND SPEED = 2.5 MIS BACKGROUND VISUAL RANGE PLUPIE- DOWNWIND OBSERVER DISTANCE DISTANCE ( I21) (I01) 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 40. 8.0 50. 9.9 75. 14.9 100. 19.9 150. 29.8 200. 39.8 250. 49.7 300. 59.7 350. 69.6 = 20. KM VISUAL PLUPX PLUME RANGE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY (%) RATIO MICRON E(L*A*B*) 3.0 0.98a -.006 0.79 2.5 0.985 -.007 0.97 1.8 0.97a -.010 1.38 1.5 0.971 -.012 1.77 1.4 0.968 -.414 1.95 1.3 0.967 -.014 2.03 1.3 0.976 -.012 1.52 1.3 0.986 -.003 0.82 1.3 0.994 -.005 0.44 1.1 0.999 -.002 0.10 0.6 1.000 -.001 0.03 0.1 1.000 -.000 0.00 0.0 1.0�0 -.000 0.00 0.0 1.000 -.000 0.00 0.0 1.000 -.000 0.00 0.0 1.000 -.000 0.00 = 50. KM VISUAL PLUMEM PLUME RANGE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY (7.) RATIO MICRON E(L*A*B*) 2.8 0.967 -.014 1.59 2.2 0.959 -.015 1.93 1.6 0.940 -.019 2.74 1.2 0.923 -.023 3.51 1.1 0.915 -.025 3.87 1.0 0.911 -.026 4.02 0.9 0.923 -.024 3.56 0.9 0.944 -.020 2.68 1.0 0.959 -.016 2.02 1.0 0.932 -.010 1.00 1.1 0.992 -.006 0.51 1.2 0.999 -.003 0.15 1.1 1.000 -.001 0.05 0.7 1.000 -.001 0.02 0.3 1.0�0 -.000 0.01 0.1 1.030 -.000 0.00 263 1000MiW COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPEED = 2.5 MIS BACKGROUND VISUAL RANGE = 100. KM PLU.MX- V I SU_AL DOIS'NWIND OBSERVER RANGE DISTANCE DISTANCE REDUCTION (KP1) (K@1) (Vol) 1. 5.0 2.6 2. 5.0 2.1 5. 5.0 1.4 10. 5.0 1.1 15. 5.0 0.9 20. 5.0 0.8 no6.0 0.7 40. 6.0 0.7 50. 9.9 0.7 75. 14.9 0.8 100. 19.9 0.8 150. 29.8 1.0 200. 39.8 1.2 250. 49.7 1.3 300. 59.7 1.5 350. 69.6 1.7 1000IYW COAL-FIRED PLANT PA',QUILL-GIFFORD D WILD SPEED = 2.5 MIS BA,:KGROUND VISUAL RANGE = 200. KM PLUN'Ei - VISUAL DO' INWIND OBSERVER R'IriYGE DISTANCE DISTANCE REDUCTION (I9I) (10) ( 7 ) 1. 5.0 2.4 2.. 5.0 1.9 5. 5.0 1.3 110. 5.0 0.9 15. 5.0 0.8 20. 5.0 0.7 30. 6.0 0.6 40. 8.0 0.6 50• 9.9 0.6 75. 14.9 0.6 100. 19.9 0.6 150. 29.8 0.8 200. 39.8 1.0 250. 49.7 1.1 300. 59.7 1.3 350. 69.6 1.6 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B*) 0.951 -.022 2.09 0.941 -.022 2.49 0.915 -.026 3.48 0.892 -.030 4.44 0.881 -.032 4.90 0.877 -.033 5.09 0.886 -.031 4.77 6.906 -.028 4.03 0.922 -.025 3.40 0.952 -.019 2.25 0.970 -.014 1.49 0.938 -.009 0.73 0.995 -.006 0.37 .0.998 -.004 0.20 1.060 -.003 0.11 1.000 -.002 0.07 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B-) 0.936 -.031 2.53 0.925 -.030 2.94 6.897 -.032 4.03 0.871 -.036 3.11 0.839 -.038 5.63 0.854 -.0= 5.84 0.860 -.037 5.62 0.877 -.034 5.04 0.892 -.031 4.50 0.921 -.026 3.44 0.942 -.022 2.64 0.966 -.018 1.71 0.9L?0 -.014 1.13 0.983 -.012 0.77 0.993 -.009 0.52 0.996 -.007 0.35 264 1000MW COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPEED = 3.0 M/S BACKGROUND V I SUAL RANGE PLUPIE- DOWNWIND OBSERVER DISTANCE DISTANCE 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 40. 8.0 50. 9.9 75. 14.9 100. 19.9 150. 29.8 200. 39.8 250. 49.7 300. 59.7 330. 69.6 100011W COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPEED = 5.0 MIS BACKGROUND VISUAL RANGE PLUPM- DO1,71- t'IND OBSERVER DISTANCE D I STAsICE ( ICI) i KtI) 1. 3.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 40. 8.0 u0. 9.9 75. 14.9 103. 19.9 150. 29.8 200. 39.8 250. 49.7 300. 59.7 350. 69.6 = 20. KM VISUAL PLUME PLUME RANGE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY (7) K4TIO MICRON E(L*A*B*) 2.4 0.993 -.004 0.49 1.6 0.990 -.005 0.64 1.1 0.983 -.007 1.02 0.9 0.978 -.009 1.32 0.8 0.976 -.010 1.42 0.8 0.976 -.010 1.42 0.7 0.934 -.007 0.96 0.7 0.993 -.004 0.49 0.7 0.997 -.003 0.25 0.6 1.000 -.001 0.05 0.3 1.430 -.000 0.01 0.0 1.030 -.000 0.00 0.0 1.000 -.000 0.00 0.0 1.0�0 -.000 0.00 0.0 1.000 -.000 0.00 0.0 1.000 -.000 0.00 = 50. KM VISUAL PLUDIE PLUME M GE CONTRAST PERCEPT- REDUCTIOfl BLUE -RED AT 0.55 IBILITY (9.) PtATI0 HICRON E(L*A*B*) 2.3 0.980 -.010 1.00 1.5 0.973 -.010 1.28 0.9 0.935 -.014 2.01 0.7 0.942 -.017 2.59 0.6 0.937 -.018 2.80 0.6 0.937 -.018 2.80 0.5 0.950 -.015 2.27 0.5 0.966 -.012 1.60 0.5 0.977 -.009 1.15 0.5 0.990 -.005 0.53 0.6 0.996 -.003 0.26 0.6 0.999 -.001 0.06 0.5 1.©.30 -.000 0.02 0.3 1.000 -.000 0.01 0.1 1.030 -.000 0.00 0.0 1.000 -.000 0.00 265 1000MW COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPEED = 5.0 MIS BACKGROUND VISUAL RANGE = 100. KM PLUME- VISUAL DOWNWIND OBSERVER RANGE DISTANCE DISTANCE REDUCTION 1. 5.0 2.1 2. 5.0 1.3 5. 5.0 0.8 10. 5.0 0.6 15. 5.0 0.5 20. 5.0 0.5 30. 6.0 0.4 40. 8.0 0.4 59. 9.9 0.4 75. 14.9 0.4 100. 19.9 0.3 150. 29.8 0.5 200. 39.8 0.6 250. 49.7 0.6 300. 59.7 0.6 350. 69.6 0.6 1000MW COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPEED = 5.0 M/S BACKGROUND VISUAL RANCE = 200. KM PLUP - V ISUAL DOWNWIND OBSER'�MR RANGE DISTANCE DISTANCE REDUCTION ( IQll ( 31) ( 7. ) 1. 5.0 1.9 2• 5.0 1.2 5. 5.0 0.7 10. 5.0 0.5 15. 5.0 0.4 2G. 5.0 0.4 30. 6.0 0.3 40. 8.0 0.3 50. 9.9 0.3 75. 14.9 0.3 100. 19.9 0.4 150. 29.8 0.4 200. 39.8 0.5 250. 49.7 0.5 300. 59.7 0.6 350. 69.6 0.6 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B*) 0.970 -.016 1.33 0.961 -.015 1.64 0.937 -.016 2.54 0.919 -.021 3.27 0.913 -.022 3.54 0.913 -.022 3.52 0.926 -.019 3.02 0.943 -.016 2.40 0.955 -.014 1.93 0.974 -.010 1.18 0.985 -.007 0.75 0.995 -.004 0.31 0.998 -.002 0.14 0.999 -.001 0.06 1.000 -.001 0.03 1.000 -.000 0.02 PLUME PLUME COITRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B*) 0.959 -.023 1.64 0.950 -.020 1.94 0.924 -.022 2.93 0.904 -.025 3.75 0.897 -.026 4.04 0.897 -.025 4.03 0.910 -.023 3.55 0.926 -.020 2.98 0.933 - . 017 2.54 0.953 -.014 1.79 0.970 -.011 1.33 0.985 -.003 0.74 0.992 -.006 0.43 0.996 -.004 0.25 0.993 -.003 0.15 0.999 -.002 0.10 MOW COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 2.5 M/S BACKGROUND VISUAL RANGE PLMA*r-- DOI%7WIND OBSERVER DISTANCE DISTANCE ( KPI) ( IUD 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 40. 8.0 50. 9.9 75. 14.9 100. 19.9 150. 29.8 200. 39.6 2GO. 49.7 303. 59.7 350. 69.6 1000MW COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 2.5 HIS BACKGROUND VISUAL FLANGE PLI PM, - DOt,'NWIND OBSERVER D I S T ANCE D I ST,:NCE (lull) (KI) 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 40. 8.0 50. 9.9 75. 14.9 100. 19.9 150. 29.8 200. 39.8 250. 49.7 300. 59.7 350. 69.6 = 20. KM VISUAL PLUME PLUME RANGE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY ( :) RATIO MICRON E(L*A*B*) 5.7 0.983 -.010 1.16 4.3 0.976 -.011 1.43 3.0 0.972 -.013 1.75 2.4 0.966 -.015 2.09 2.2 0.962 -.017 2.35 2.1 0.959 -.018 2.54 2.1 0.967 -.017 2.09 2.2 0.933 -.012 1.22 2.3 0.991 -.008 0.70 2.2 0.999 -.003 0.18 1.1 1.000 -.001 0.05 0.0 1.0w3 -.000 0.01 0.0 1.0^0 -.000 0.00 0.0 1.0^0 -.O00 0.00 0.0 1.000 -.O00 0.00 0.0 1.000 -.00O 0.00 = 50. KM VIS;TAL PLTJIE PLUME R.Al GE COI(TILkST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY (9.) RATIO MICRON E(L*A*.B*) 5.3 0.952 -.023 2.41 3.9 0.940 -.024 2.68 2.6 0.925 -.026 3.48 2.0 0.909 -.029 4.16 1.8 0.893 -.032 4.67 1.7 0.890 -.034 5.05 1.6 0.895 -.034 4.93 1.7 0.917 -.031 4.03 1.8 0.937 -.027 3.20 1.9 0.970 -.O13 1.69 1.9 0.987 -.011 0.86 2.1 0.993 -.005 0.25 2.1 1.000 -.002 0.09 1.2 1.000 -.001 0.04 0.3 1.0%30 -.000 0.02 0.0 1.000 -.000 0.01 267 1000MW COAL-FIRED PLANT PASCUILL-GIFFORD E WIND SPED = 2.5 MIS BACKGROUND I' I SUAL RANGE = 100. KM PLWIE- VISUAL DOt;TiWIND OBSERVER R Il GE DISTANCE DISTANCE REDUCTION ( I.3'1) ( K?I) (%) 1. 5.0 5.0 2 5.0 3.6 S. 5.0 2.4 10. 5.0 1.8 15. 5..0 1.6 20. 5.0 1.a1 30. 6.0 1.3 4.0. 8.0 1.4 50. 9.9 1.4 75. 14.9 1.5 100. 19.9 1.6 150. 29.8 1.8 1203. 39.8 2.0 250. 49.7 2.3 31.50. 59.7 2.4 350. 69.6 2.7 1000MW COAL-FIRED PLANT PASlY ILL-GIFFOIL'i E WIND SPEED = 2.5 MIS BACKGROUND VISUAL RAPIGE = 200. KM PLMM- VISUAL DOi:'IlWIFD OBSER«R RANGE DISTANCE DISTAI:CE REDUCTION 1. 5.0 4.5 2. 5.0 3.3 5. 5.0 2.1 10. 5.0 1.6 15. 5.0 1.4 20. 5.0 1.2 30. 6.0 1.1 40. 8.0 1.1 50. 9.9 1.1 75. 14.9 1.2 100. 19.9 1.2 150. 29.8 1.4 200. 39.£3 1.7 230. 49.7 2.0 3GO. 59.7 2.2 350. 69.6 2.4 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B*) 0.928 -.036 3.20 0.912 -.035 3.74 0.894 -.035 4.46 0.873 -.038 5.30 0.853 -.041 5.94 0.847 -.043 6.43 0.84cc -.045 6.64 0.860 - . 04le 6.10 0.879 -.0E1 5.44 0.920 -.033 3.81 0.930 -.026 2.54 0.980 -.016 1.22 0.992 -.010 0.60 0.997 -.007 0.32 0.999 -.004 0.16 1.000 -.003 0.11 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B*) 0.902 -.053 3.93 0.8Q3 -.043 4.46 0.81,19 -.045 5.20 0.8'7 -.05 6.13 0.830 -.049 6.C6 0.817 -.051 7.41 0.809 -.034 7.88 0.817 -.05Y 7.63 0.830 -.053 7.26 0.868 -.04Z 5.88 0.903 -.040 4.53 0.944 -.031 2.87 0.968 -.024 1.84 0.901 -.019 1.23 0.9"9 -.015 0.84 0.993 -.012 0.59 100011W COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 5.0 HIS BACKGROUND VISUAL RANGE PLUME- DOWNkIND OBSEM7ER DISTANCE DISTANCE ( Ia1) ( Irl) 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 4t3. 8.0 50. 9.9 75. 14.9 100. 19.9 150. 29.8 200. 39.8 250. 49.7 300. 59.7 353. 69.6 1O00MW COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 5.0 M'S BACKGRO ND V I SUAL. RANGE PLUI-M- DOWNWIIiD OBSERVER DISTANCE DISTANCE (I0:1) ( IQI) 1. 5.0 2. 5.0 3. 5.0 1,). 5.0 1:i. 5.0 20 5.0 30. 6.0 40. 8.0 50. 9.9 75. 14.9 100. 19.9 150. 29.8 200. 39.8 250. 49.7 300. 59.7 350. 69.6 = 20. KM VISUAL PLUME PLUME RANGE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY (7.) RATIO MICRON E(L*A*B*) 3.4 0.991 -.006 0.64 2.3 0.989 -.006 0.74 1.6 0.983 -.007 1.03 1.3 0.977 -.010 1.39 1.2 0.973 -.011 1.61 1.2 0.971 -.012 1.76 1.2 0.977 -.011 1.43 1.2 0.988 -.008 0.81 1.3 0.994 -.005 0.45 1.2 0.999 -.062 0.10 0.6 1.000 -.001 0.03 0.0 1.O00 -.000 0.00 0.0 1.000 -.000 0.00 0.0 1.000 -.000 0.00 0.0 1.000 -.000 0.00 0.0 1.000 -.000 0.00 = 50. KM VISUAL PLUME PLUME RANGE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY ( ^) P14TI0 MICRON E(L*A*B*) 3.2 0.974 -.013 1.32 2.1 0.969 -.012 1.47 1.4 0.955 -.015 2.05 1.1 0.939 -.018 2.75 1.0 0.929 -.021 3.19 0.9 0.923 -.023 3.43 0.9 0.927 -.023 3.35 0.9 0.945 -.020 2.64 1.0 0.959 -.016 2.03 1.0 0.932 -.010 1.01 1.0 0.992 -.006 0.50 1.1 0.999 -.002 0.13 1.0 1.000 -.001 0.04 0.5 1.000 -.000 0.01 0.1 1.000 -.000 0.01 0.0 1.000 -.000 0.00 1090MV CO.4I.-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 5.0 WS BACKGROUND VISUAL RANCE = 100. KM PI,T1r.nLE- VI SUAL D01-11MIND OBSEMM. R. LANGE DISi10ZE DISTAICE rZ!XCTICN ( MID ( II-1) M) 1. 5.0 3.0 2. 5.0 2.0 G. 5.0 1.2 10. 5.0 0.9 1:1. 5.0 0.3 20. 5.0 0.8 30. 6.0 0.7 40. 8.0 0.7 50. 9.9 0.8 75. 14.9 0.8 100. 19.9 0.3 150. 29.8 0.9 200. 39.3 0.9 200. 49.7 0.9 300. 59.7 0.9 350. 69.6 0.9 1000MW CO.1L-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 5.0 I/S BACKGROLTD VISUAL RANGE = 200. KM PLIIIT- VISUAL DOIN74WIND OBSE13iFER RAGE DISTANCE DISTANCE REDUCTION (ICI) (KID (0) 1. 5.0 2.7 2. 5.0 1.8 5. 5.0 1.1 10. 5.0 0.8 15. 5.0 0.7 20. 5.0 0.6 30. 6.0 0.6 1 0. 8.0 0.6 50. 9.9 0.6 75. 14.9 0.6 100. 19.9 0.6 150. 29.8 0.7 11'00. 39.8 0.8 150. 49.7 0.3 100. 59.7 0.8 150. 69.6 0.3 PLUM PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY P,4TI0 MICRON E(L*A*B*) 0.961 -.0?1 1.76 0.953 -.018 1.92 0.937 -.020 2.60 0.915 -.024 3.48 0.902 -.02G 4.03 0.893 -.023 4.41 0.692 -.029 4.48 0.907 -.027 3.97 0.922 -.025 3.42 0.952 -.019 2.26 0.971 -1014 1.47 0.990 -.003 0.62 0.997 -.004. 0.27 0.999 -.003 0.12 1.000 -.001 0.06 1:000 -.001 0.03 PLUM PLUM- CONTRP.ST PERCEPT - BLUE -RED AT 0.55 IBILITY R4TIO MICRON E(L*A*B*) 0.945 -.031 2.19 0.91I -.026 2.29 0.922 .025 3.02 0.893 -.029 4.00 0.633 -.0121 4.63 0.872 -.033 5.05 0.2G8 -.G35 5.28 0.879 -.033 4.96 0.891 -.43? 4.53 0.920 -.026 3.46 0.943 -.022 2.60 0.971 -.015 1.46 0.935 -.011 0.82 0.993 -.007 0.46 0.996 -.005 0.28 0.993 0.17 270 1000MW COAL-FIRED PLANT PASQUILL-GIFFGI`JD F WIND SPEED = 2.5 MIS BACKGROUND VISUAL R4NGE PLUI'IE- DOWNW114D OBSERVER DISl'ANC.E DISTAINCE ( 0) 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 40. 0.0 50. 9.9 75. 14.9 100. 19.9 150. 29.6 200. 39.8 250. 49.7 300. 59.7 3::0. 69.6 1000MW COAL-FIRED PLANT PASQUILL-GIFFORD F WIND SPEED = 2.5 PIS BACKGROUND VISUAL A.60GE PLUI.7:- DOWNWIIiD OBSERVER DISTANCE DISTAI'CE (IU'U (ILi� 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 40. a.O 50. 9.9 75. 14.9 100. 19.9 150. 29.6 200. 39.8 250. 49.7 v00. 59.7 350. 69.6 = 20. KM V I S U.4L PLUME PLUME RANGE CONTRAST PERCEPT - REDUCTION BLUE-n-D AT 0.55 IBILITY (7.) PATIO MICRON E(L*A*B*) 7.7 0.973 -.Olc 1.57 6.4 0.9163 -.017 2.15 4.6 0.939 -.020 2.63 3.9 0.955 -.021 2.84 3.6 0.952 -.022 3.00 3.4 0.')49 -.023 3.16 3.3 0.)61 -.021 2.57 3.5 0.979 -.015 1.50- 3.E 0.990 -.011 0.88 3.3 0.999 -.005 0.25 1.8 1.01VI0 -.002 0.09 0.0 1.000 -.GCO 0.01 0.0 1.0110 -.00O 0.00 0.0 1.0, -.00O 0.00 0.0 1.000 -.000 0.00 0.0 1.0010 - . 000 0.00 = 50 . ri-I VISUAL. PLUPIE PLUME RANGE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.53 IBILITY (:) RATIO MICRON E(L*A*B*) 7.3 0.936 -.031 3.22 5.9 0.910 -.036 4.34 4.3 0.8,13 -.040 5.2a 3.4 0.8713 - . 041 5.70 3.0 0.871 -.043 6.02 2.8 0.3-11Z -.044 6.34 2.7 0.672 -.044 6.09 2.6 0.899 -.040 5.00 2.9 0.922 -.036 4.05 3.2 0.960 -.027 2.34 3.5 0.931 -.0!9 1.33 3.9 0.996 -.009 0.46 4.2 1.000 -.004 0.19 1.9 1.O 0 -.002 0.09 0.1 1.010 -.001 0.04 0.0 1.000 -.003 0.02 271 1000MW COIL -FIRED PLANT PASQUILL" IFFORD F WIND SPEL-O = 2.5 MIS BACKGROUND VISUAL ILANGE = 100. 101 FLUtX- VISU4L PLUME PLUME D0AMWI IZD OBSFRIT- R RINGE CONTRAST PERCEPT- DISTA111C.E DISTANCE REDUCTION BLUE -RED AT 0.55 IBILITY (121) ( y?•t) ( n) PtAT10 MICP,ON E(L*A*B,-) 1. 5.0 6.6 0.904 -.046 4.29 2. 5.0 5.4 0.869 -.052 5.66 5. 5.0 3.9 0.841 -.054 6.61 10. 5.0 3.0 0.31>9 -.054. 7.31 15. 5.0 2.7 0.830 -.056 7.72 20. 5.0 2.5 0.810 -.057 8.12 30. 6.0 2.3 0.810 -.059 8.26 40. 8.0 2.3 0.829 -.058 7.62 50. 9.9 2.4 0.8T3 -.056 6.94•- 75. 14.9 2.6 0.391 -.050 5.32 100. 19.9 2.9 0.9115 -.043 3.96 150. 29.8 3.4 0.966 -.031 2.14 200. 39.8 3.7 0.986 -.021 1.17 250. 49.7 4.0 0.9n:l5 -.015 0.66 3CO. 59.7 4.2 0.999 -.010 0.42 330.1 69.6 4.5 1.030 -.007 0.28 1000MW COAL-FIRED PLANT PASQUILL-GIFFORD F WIND SPEED = 2.5 NIS BACKGROU.1) VISUAL IL41,"GE = 200. F.TI PLUNZ- VISUAL PLUME PLUME DOI-MINI) OBSERVER P4-1:11E CONTRAST PERCLPT- DISTANCE DISTEiNCE REDUCTION BLUE -RED AT 0.55 IBILITY (121) ( ICI) ( �) RATIO MICRON E(L*AXB*) 1. 3.0 6.2 0.871 -.070 5.27 2. 5.0 4.9 0.833 -.071 6.75 5. 5.0 3.5 0.804 -.069 7.98 10. 5.0 2.7 0.791% -.667 8.31 15. 5.0 2.4 0.7%ca2 -.CGF. 8.96 20. 5.0 2.2 0.772 -.069 9.42 30. 6.0 2.0 0.765 -.072 9.85 10. 8.0 2.0 0.775 -.072 9.66 50. 9.9 2.0 0.737 -.072 9.34 75. 14.9 2.1 0.820 -.070 8.30 IGO. 19.9 2.2 0.052 -.067 7.14 150. 29.un 2.6 0.9�8 -.056 5.08 200. 39.3 3.0 0.941 -.049 3.56 250. e9.7 3.3 0.964 -.0111 2.52 300. 59.7 3.6 0.979 -.034• 1.62 350. 69.6 4.0 0.937 -.020 1.35 272 1000MW COAL-FIRED PLANT PASQUILL-CIFFORD F FIND SPEED = 5.0 M/S BACKGROUND VISUAL RANGE PLUPIE- DOIN7WINn O13FERVER DISTANCL DISTANCE 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 40. 6.0 50. 9.9 75. 14.9 100. 19.9 150. 29.8 200. 39.8 250. 49.7 300. 59.7 350. 69.6 1000MW COAL-FIRED PLANT PASQUIL L-GIFFORD F WIND SPEED = 5.0 Pt,'S BACKCROUND VISUAL R. _NGE PLUi Z- DOINNWII,D OBSERVE'P. DISTANCE DISTANCE ( IU'I) ( Ili) 1. 5.0 2. 3.0 5. 5.0 10. 5.0 15. 5.0 20. 5.6 30. 6.0 40. 8.0 50. 9.9 75. 14.9 100. 19.9 150. 19.8 200. 39.8 250. 49.7 300. 59.7 350. 69.6 = 20. KM. VISUAL PLUME PLUME RAF GE CONTRAST PERCEPT- REZDUCTION BLUE -RED AT 0.55 IBILITY (%) RATIO MICRON E(L*A*B*) 4.5 0.990 -.007 0.76 3.4 0.987 -.007 0.90 2.4 0.982 -.008 1.12 1.9 0.977 -.010 1.41 1.8 0.973 -.012 1.65 1.7 0.970 -.013 1.83 1.8 0.975 -.012 1.58 1.9 0.937 -.009 0.96 2.0 0.993 -.007 0.57 2.1 0.999 -.003 0.16 1.1 1.0103 -.001 0.05 0.0 1.000 -.00O 0.01 0.0 1.0,00' -.000 0.00 0.0 1.0r.0 -.000 0.00 0.0 1.0^0 -.000 0.00 0.0 1.000 -.000 0.00 = 50 . KI`I V I S U L PLUt , PLUMLE R FGE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY 016) RAT 10 MICF.ON E( L*A.:;B-) 4.2 0.970 -.016 1.57 3.1 0.903 -.016 1.1'1 2.1 0.952 -.017 2.23 1.7 0.939 -.020 2.79 1.5 0.923 -.022 3.26 1.4 0.920 -.024 3.63 1.4 0.920 -.026 3.71 1.5 0.933 -.024 3.16 1.6 0.943 -.022 2.62 1.3 0.973 -.016 1.53 1.9 0.937 -.012 0.3a 2.1 0.993 -.005 0.23 2.2 1.000 -.002 0.10 1.1 1.0�0 -.001 0.03 0.1 1.000 -.000 0.02 0.0 1.0u0 -.OGO 0.01 273 1000MW COAL-FIRED PLANT PASQUILL-GIFFORD F WIND SPEED = 5.0 PITS ByCKGROUI:D V I SUAL R4NGE = 100. ICI PLUMEE- VISUAL DOS=71.1IND OB3E 7ER RAT(.- C DISTANCE DISTAICE P.ELUCT'ION ( Iu•I) ( I3I) ( � i 1. 5.0 4.0 2. 5.0 2.9 5. 5.0 2.0 10. 5.0 1.5 15. 5.0 1.3 20. 5.0 1.2 30. 6.0 1.2 40. 8.0 1.2 50. 9.9 1.3 75. 14.9 1.4 100. 19.9 1.6 150. 29.6 1.3 2G3. 39.0 1.9 250. 49.7 2.0 3G0. 59.7 2.1 350. 69.6 2.1 1000MW COAL-FIRED PLANT PASQUILL-GIFFORD F WIND SPEED = 5.0 M,S LACKGROUB'D VISUAL RAC,iT: = 230. 101 PLUMEE- VISE �y DOV7 WII19 OBSER17ER R� �'GE DISTANCE DISTANCE REDUCTIOii (12D (mi) (7.) 1. 5.0 3.5 2. 5.0 2.0 5. 5.0 1.7 10. 5.0 1.3 13. 5.0 1.2 23. 5.0 1.1 30. 6.0 1.0 40. 6.0 1.0 50. 9.9 1.0 75. 1I..9 1.1 100. 19.9 1.2 11"0. 2=).3 1.4 2c0. 39.8 1.5 230. 4.9.7 1.7 3C0. 59.7 1.8 3:,3. 69.6 1.9 PLUME PLUME COIiTR LST PERCEPT - BLUE -RED AT 0.55 IBILITY RAT 10 111CRON E(L*A--B*) 0.953 -.026 2.12 0.945 -.024 2.33 0.931 -.024 2.86 0.914 -.026 3.56 0.9c3 -.029 4.14 0.8E3 -.032 4.61 0.3 1 - . 034 4.98 0.890 -.034 4.77 0.9C3 -.034 4.44 0.927 -.030 3.4.5 0.950 -.026 2.55 0.970 -.0?E 1.33 0.991 -.0?2 0.69 0.957 -.013 0.33 0.999 -.003 0.22 1.000 -.003 0.14 PLTTiZ-; PLUiT, C011TILART PERCEPT - BLUE -RED AT 0.55 IBILITY P� TI0 111CRON E(L*A*B*) 0.934 -.0110 2.66 0.927 -.0115 2.87 0.914 - . 032 3.36 0.395 -.033 4.12 0.879 -.0`6 4.78 O.`56 -,033 5.31 0.8� 5.90 G.8,5 -.043 5.99 0.8110 5.91 0.830 -.042 5.32 0.903 -.040 4.54 0.940 -.033 3.13 0.964 -.027 2.11 0.979 -.022 1.43 0.9^3 -.017 0.99 0.993 -.014 0.71 274 2000MW COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPE•-73 = 2.5 MIS BACICGROLii D VISUAL RAIZ GE PLUKE- DOX%74W I N D OBSERVER DISTANCE DISTP_I:CE (IQ•1) ( I1•1) 1. 5.0 2. 5.0 5. 5.0 10. 5.0 13. 5.0 20. 5.0 30. 6.0 4.0. 8.0 50. 9.9 75. 14.9 103. 19.9 150. 29.3 200. 39.8 250. 49.7 3G0. 59.7 330. 69.6 1000MW COAL-F I RED PLANT PASOUILL-GIFF07RD C WIND SPEED = 2.5 IIS BACKGROUND V I SU a T. RANGE PL= -- DOWNWIND OBSER:.'ER DISTANCE DISTANCE 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 40. 3.0 50. 9.9 75. 14.9 100. 19.9 ISO. 29.8 200. 39.3 250. 49.7 300. 59.7 350. 69.6 = 20. KM VISU1AL PLUME- PLUME R FGE CG14TR.AST PERCEPT - RE DI T 10N BLUEE-RED AT 0.55 I B I L I TY ( ;. ) RAT 10 PI I CP,ON E(L*A*B* ) 4.6 0.938 -.003 0.88 2.3 0.933 -.003 1.10 1.4 0.932 -.003 1.12 1.2 0.977 -.010 1.39 1.3 0.970 -.012 1.80 1.4 0.965 -.015 2.14 1.5 0.972 -.014 1.77 1.6 0.9�5 -.010 1.04 1.7 0.993 -.007 0.59 1.5 0.999 -.003 0.15 0.9 1.CC3 -.001 0.04 0.3 1.C^3 -.000 0.01 0.1 1.0^3 -.COO 0.00 0.0 1.C^0 -.000 0.00 0.0 1.G^0 -.00O 0.00 0.0 -.00O 0.00 = 50. KM V I S J_-- L P LUI•2,; PLUP, M RAI:GZ C014TRAST PERCEPT - RE D("TION BLUE -RED AT 0.55 IBILITY (7.) RATIO PIICF,011 E(L*A*B',`) 4.5 0.964 -.013 1.81 2.0 0.9:. .010 2.20 1.2 0.951 -.015 2.21 1.0 G.939 -.013 2.73 1.0 0.92' -.023 3.56 1.0 0.9G7 -.027 4.23 1.1 0.910 -.023 4.16 1.2 0.929 -.026 3.41 1.3 0.946 -.022 2.70 1.5 0.975 -.0115 1.41 1.6 0.9`9 -.009 0.72 1.9 0.91:3 -.004 0.22 1.7 1.030 -.002 0.00 1.1 1.000 -.001 0.04 0.6 1.010 -.003 0.02 -.C:;O 0.01 275 2000M1i COAL-FIRED FLANT PASQUILL-GIFFORD C WIND SPEED = 2.5 NIS BACKGROUND VISUAL RANGE = 100. KM PLUPT,-- VIISUAL DOWNitiIND OBSERVI"a R'_I\(-L DISTANCE DISTANCE RED 'CTIOIl (Ial) ( KIN) (7.) 1. 5.0 4.2 2. 5.0 2.4 5. 5.0 1.1 10. 5.0 0.3 15. 5.0 0.8 20. 5.0 0.8 30. 6.0 0.9 40. 8.0 1.0 50. 9.9 1.0 75. 14.9 1.2 100. 19.9 1.3 150. 29.8 1.6 2G0. 39.8 1.9 250. 49.7 2.1 300. 59.7 2.4 350. 69.6 2.6 2000NW COAL-FIRED PLANT PASO-UILL-GIFF0:3D C WIND SPZ D = 2.5 NIS BACKGROUND VISUAL RANGE = 200. IQ1 PLTME- VISUAL DOWNWIND OBSERVER RANGE DISTANCE DISTANCE REDUCTION (R7.1) (IM) (7. 1. 5.0 3.9 2. 5.0 2.1 5. 5.0 1.0 10. 5.0 0.7 15. 5.0 0.7 20. 5.0 0.7 30. 6.0 0.7 ~0• 8.0 0.8 50. 9.9 0.8 73. 14.9 0.9 1G0. 19.9 1.0 150. 29.8 1.3 200. 39.8 1.6 270. 4.9.7 1.3 3('0. 59.7 2.1 350. 69.6 2.5 Ar PLUM PLMIE COIITRAST PERCEPT- BLUF-RED AT 0.55 IBILITY RAT 10 NI CRON E(L*A*By,-) 0.9z6 -.029 2.43 0.932 -.025 2.84 0.931 -.020 2.81 0.915 -.023 3.46 0.891 -.029 4.50 0.871 -.034 5.36 0.3u7 -.037 5.58 0.331 -.036 5.14 0.897 -.034 4.56 0.933 -.027 3.16 0.9va -.021 2.12 0.932 -.014 1.07 0.9r'3 -.0;0 0.55 0.997 -.006 0.31 0.9^9 -.004 0.18 1 .01)o - . 003 0.11 PLUM PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO NICROI4 E(L*AWBe) 0.925 -.043 3.02 0.914 -.034 3.36 0.917 -.025 3.24 0.899 -.023 3.97 0.870 -.034 5.16 0.8.6 -.04.0 6.15 0.--F -.04.3 6.59 0.345 -.044 6.45 0.856 -.043 6.07 0.1990 -.038 4.86 0.913 -.033 3.77 0.951 - . 027 2.52 0.970 -.022 1.70 0.932 -.013 1.19 0.91;0 -,015 0.E0 0.994 -.012 0.56 276 20000MW CO_N.-F I RED PLAN PASQUILL-GIFFORD C WIND SPEED = 5.0 M/S BACKGROUND V I SUAL RANGE = 20. P1'I pol?NWIND PLUM- OBSERVER V I SU.XL R4IC -E PLUM PLUM DISTANCE DISTANCE REDUCTION BLUE -RED C014TRf--IQT AT 0.55 PERCEPT - IBILITY ( IUI) 1. (lal) 5.0 (7.) M4TI0 M1 CI:O1l E(L*A*BW ) .2 5.0 2.6 1.5 0.991 0.937 -.005 0.61 5. 5.0 0.9 0.931 -.COG -.008 0.82 1.17 10. 5.0 0.3 0.979 -.00R: 1.27 15. 20. 5.0 5.0 0.8 0.977 -.009 1.36 30. 6.0 0.8 0.3 0.976 0.9S'2 -.010 -1009 1.46 40• E•0 0.9 0.991 -.00G 1.14 0.64 50. 9.9 1.0 0.995 -.004 0.36 75. 14.9 0.9 0.999 -.00I 0.09 100. 19.9 0.5 1.010 -.001 0.03 150. 29.8 0.2 ].CEO -.000 0.00 200. 39.8 0.0 1.0^0 -.00O 0.00 23 0. 49.7 0.0 1.0^0 0.00 300. 59.7 0.0 1.0C -.000 0.00 350. 69.6 0.0 1.ov" -.0C3 0.00 2000NW COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPEED = 5.0 MIS BACKGROUND VISUAL R:'O%GE = 50. KPI PLUI`r- V I SUAL PLUM PLUIZ DOI-04WITID OBSE. P.VER R.kN ,E C014TRLST PEP.CEPT- DISTAfiCE DISTANCE REDUCTION BLUE -RED AT 0.53 IBILITY ( HII) ( I:?:) ( ) R__- IO MICP.CN E( 1• 5.0 2.4 0.973 -.012 1.24 2 5.0 1.3 0.965 -.012 1.62 5. 5.0 0.7 0.949 -.015 2.30 10. 5.0 0.6 0.944 -.016 2.50 15. 5.0 0.6 0.90 -.017 2.69 20• 5.0 0.6 0.9C5 -.013 2.C3 CO. 6.0 0.6 0.9:2 -.0iv 2.65 40. 3.0 0.7 0. -.OIG 2.10 50. 9.9 0.7 0.967 -.013 1.6r, 75. 14.9 0.9 0.935 -.009 0.86 100. 19.9 0.9 0.953 -.006 0.45 150. 29.8 1.0 0.999 -.002 0.12 200. 39.8 0.9 1.01,10 -.001 0.04 2L0. 49.7 0.5 1.000 -.00G 0.02 300. 59.7 0.3 1.000 -.000 0.01 350. 69.6 0.2 1 . CGcO -.000 0.00 277 2000MW COAL-FIRED PLANT PASQUILL-GIFFORD C WIND SPEED = 5.0 PINS BACKGROUND VISUAL RANGE - 100. KM PLUNLE- VISUAL DOliNWIII) OBSERVER pl;kNGE DISTANCE DISTARCE REDUCTION 1. 5.0 2.3 2 5.0 1.2 5. 5.0 0.6 10. 5.0 0.5 15. 5.0 0.4 20. 5.0 0.4 30. 6.0 0.5 40. 8.0 0.5 50. 9.9 0.6 75. 14.9 0.7 100. 19.9 0.3 150. 29.8 0.9 203. 39.8 1.0 250. 49.7 1.0 300. 59.7 1.1 350. 69.6 1.1 2000NW COAL-FIRED PLANT PASQUILL-GIFFORD C 'WIND SPEED = 5.0 N/S BACKGROUND VISUAL RAP:GE = 200. KPI PLUPIE- V I S U.AL DOWNWIND OBSERVER RANGE DISTAWCE DISTANCE REDUCTION CIi-D (3) 1. 5.0 2.0 �. 5.0 1.1 3. 5.0 0.5 10. 5.0 0.4 15. 5.0 0.4 20. 5.0 0.4 3c�. 6.0 0.4 40. 8.0 0.4 5C. 9.9 0.4 ?�. 14.9 0.5 19.9 0.6 150. 29.8 0.7 200. 39.3 0.3 2501. <9.7 0.9 300. 59.7 1.0 330. 69.6 1.0 PLUME PLUME COiiTRn.ST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B*) 0.962 -.018 1.64 0.950 -.017 2.07 0.929 -.019 2.90 0.922 -.020 3.15 0.917 -.021 3.38 0.911 -.023 3.63 0.914 -.023 3.53 0.926 -.021 3.14 0.937 -.020 2.75 0.959 -.016 1.91 0.974 -.013 1.31 0.9:0 -.00Lj 0.60 0.996 -.005 0.28 0.999 -.O03 0.14 1.000 - . 00`_' 0.07 1.000 -.001 0.04 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICnOU E(L*A*B:r:) 0.949 -.026 1.99 0.938 -.022 2.4-1 0.915 -.022 3.32 0.903 -.023 3.60 0.901 - . 0'24 3.87 0.894 -.026 4.15 0.8915 -.026 4.15 0.903 -.026 3.92 0.912 -.025 3.64 0.93= -.022 2.93 0.949 -.020 2.32 0.972 -.015 1.52 0.935 -.011 0.87 0.992 -.003 0.53 - . OOG 0.33 0.993 -.005 0.21 278 2003P;W COA!.-F I RED PLANT PASQUILL-GIFFORU D WIND SPED = 2.5 MIS BACKGROUND VISUAL R-1VGE PLUPE:- DO?-,'NWINJ OBSERVER DISTAJ40E DIST?JIICE (ICH) ( IUD 1. 5.0 2 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 40. 8.0 �0. 9.9 75. 14.9 1GO. 19.9 150. 29.3 200. 39.8 250. �9.7 300. 59.7 350. 69.6 2000MW COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPEED = 2.5 MIS BACKGROUND V I SU_4L RANGE PLUME - DOWNWIND OBSERVER DISTANCE DISTANCE ( 01) ( I. 11) 1. 5.0 2. 3.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 40. 8.0 50. 9.9 75. 14.9 100. 19.9 150. 29.8 2010. 39.8 250. 49.7 300. 59.7 350. 69.6 = 20. 101 V ICTT_kL PLUME PLUI'IE R=_I;GE CONTRA T PERCEPT- rtE• DUCT I ON BLUE-F"D AT 0.55 I B I L I TY ( 7.) PIT 10 MICRON E(L*A-.,B':,) 6.0 0.926 -.009 1.06 4.3 0.920 -.011 1.35 3.5 0.971 .014 1.34 2.3 0.963 -.017 2.33 2.4 0.939 -.015 2.54 2.3 0.957 -.019 2.63 2.1 0.1�63 -.016 2.07 2.2 0.914 -.011 1.17 2.2 0.9:2 -.CG2 0.66 2.0 0.9^9 -.O03 0.17 1.1 1.010 -.G01 0.05 0.1 1.000 -.000 0.01 0.0 1.Ong -.000 0.00 0.0 1.013 -.000 O.GO 0.0 1.03 -.GIGO 0.00 0.0 1.0IG3 -.E00 0.00 = 50 . 101 VISUAL PLUME PLUME RANGE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.53 IBILITY (7) RATIO MICRON E(L*A*B*) 5.6 0.958 -.022 2.18 4.4 0.9441 -.024 2.72 3.1 0.921 -.023 3.69 2.3 0.899 -.032 4.65 2.0 0.890 -.034 5.07 1.8 0.836 -.035 5.25 1.7 0.896 -.034 4.88 1.7 0.920 -.030 3.87 1.7 0.940 -.026 3.04 1.9 0.971 -.018 1.64 1.9 0.937 -.012 0.87 2.2 0.993 -.005 0.28 2.0 1.01�0 -.002 0.10 1.2 I.Oro -.001 0.05 0.4 1.000 -.001 0.02 0.1 1.000 -.000 0.01 279 2000MW COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPEED = 2.5 MIS BACKGROUND VISUAL RANGE = 100. KM PLUME- VISUAL PLUME PLUME DOWNWIND OBSERVER RANGE CONTRAST PERCEPT - DISTANCE D4STANCE REDUCTION BLUE -RED AT 0.55 IBILITY (KI1) (K?D (7.) RATIO MICRON E(L*A*B*) 1. 5.0 5.3 0.935 -.035 2.93 2. 5.0 4.1 0.917 -.035 3.57 5. 5.0 2.8 0.883 -.038 4.73 10. 5.0 2.1 0.859 -.042 5.93 15. 5.0 1.7 0.847 -.044 6.46 20. 5.0 1.5 0.8-41 -.045 6.69 30. 6.0 1.4 0.846 -.045 6.57 40. 8.0 1.3 0.866 -.042 5.85 50. 9.9 1.4 0.834 -.039 5.17 75. 14.9 1.5 0.922 -.033 3.70 100. 19.9 1.6 0.949 -.026 2.38 150. 29.8 1.3 0.973 -.018 1.33 200. 39.8 2.0 0.991 -.012 0.70 250. 49.7 2.2 0.997 -.003 0.40 300. 59.7 2.4 0.999 -.005 0.23 350. 69.6 2.6 1.000 -.004 0.15 200011W COAL-FIRED PLANT PASQUILL-GIFFORD D WIND SPEED = 2.5 M/S BACKGROUND VISUAL RANGE = 200. KM PLUMEM- VISUAL. PLUIME PLUME DOWNWIND OBSERVER RANGE CONTRAST PERCEPT - DISTANCE DISTAI,CE REDUCTION BLUE -RED AT 0.55 IBILITY ( I0) (101) ( 7) RATIO MI CRON E(L*A*B*) 1. 5.0 4.8 0.910 -.053 3.65 2. 5.0 3.7 0.892 -.030 4.29 5. 5.0 2.5 0.861 -.049 5.53 10. 5.0 1.8 0.829 -.052 6.87 15. 5.0 1.5 0.816 -.053 7.45 213. 5.0 1.3 0.810 -.053 7.71 30. 6.0 1.1 0.811 -.053 7.79 40. 8.0 1.1 0.824 -.052 7.36 50. 9.9 1.1 0.833 -.050 6.89 75. 14.9 1.1 0.872 -.045 5.72 100. 19.9 1.2 0.901 -.0SO 4.61 150. 29.8 1.4 0.939 -.033 3.14 200. 39.8 1.6 0.963 -.027 2.13 250. 49.7 1.9 0.971, -.023 1.50 300. 59.7 2.1 0.9,07 -.01� 1.04 330. 69.6 2.3 0.992 -.015 0.74 2000MW C0AL-FIRED PLANT PASOUILL-GIFFORD D KIND SP-ED = 5.0 NIS BACKGROUI4D VISUAL RANGE = 20. 1,21 PLUI,2:- V I SUAL PLUME PLUME DOWNW114D OBSERVED RANGE CONTRAST PERCEPT - DISTANCE DISTAJ4CE REDUCTION BLUE -RED AT 0.55 IBILITY Gal) ( M. D ( r.) K-ITIO NICROIT E(L*A*B:,,) 1. 5.0 4.G 0.991 -.007 0.70 2. 5.0 3.1 0.907 -.007 0.87 5. 5.0 2.0 0.91-0 -.009 1.27 10. 5.0 1.6 0.972 -.012 1.71 13. 5.0 1.4 0.963 -.014 1.95 20. 3.0 1.3 0.966 -.014 2.03 30. 6.0 1.3 0.975 -.012 1.60 43. 3.0 1.3 0.913 -.003 0.86 50. 9.9 1.3 0.93er -.00S 0.45 75. 14.9 1.1 0.9,9 -.002 0.10 100. 17.9 0.6 1.0^0 0.03 150. 29.8 0.1 1.0^0 -.000 0.00 200. 3?.0 0.0 1.000 -.Oc0 0.00 250. 49.7 0.0 I.G03 -.0co 0.00 300. 59.7 0.0 1.0^0 -.000 0.00 350. 69.6 0.0 1.G30 -.000 0.00 2000PIK COAL-F I RED PLANT PASCUILL-GIFF070. D HIND SPEED = 5.0 NIS BACKGROUND VISUAL RAI:CE = 50. KM PL'.)I•" - V I SL' 1. PLUME PLUM DOlill-T II D OE:3EP VZR R.:,EGE COIITP'-ST PERCEPT- D I STANCE D I S71 f;I"cE REDUCTION BLUE -REED AT 0.55 I B I L I TY ( 0.1) ( IO:) (► PLAT10111CRON E(L*A*B*) 1. 5.0 4.5 0.973 -.016 1.45 2. 5.0 2.9, 0.9G1 -.015 1.75 5. 5.0 1 7 0.9 3 -.010 2.53 10. 5.0 1 3 0.925 -.023 3.38 15. 5.0 1 1 0.915 -.C25 3.96 20. 5.0 1.0 0.9C9 -.027 4.12 20. 6.0 1.0 0.919 -.025 3.74 E.0 1.01 0.9v" l -.021 2.30 50. 9.9 1.0 0.933 -.017 2.07 75. 14.9 1.0 0.9E2 -.010 0.99 100. 19.9 1.0 0.992 -.006 0.49 150. 29.3 1.1 0.999 -.002 0.13 200. 39.8 0.9 i.00O -.001 0.04 49.7 0.5 1.0�3 -.000 0.02 300. 59.7 0.2 1.000 -.000 0.01 330. 69.6 0.1 1.0r -.000 0.00 281 2000MW COAL-FIRED PLANT PASQUILL-CIFFORD D FIND SPEED = 5.0 MIS BACKGROUND VISUAL RANGE = 100. KM PLUPE- V I S UAL DO14T4WIND OBSERVER RANGE DISTANCE DISTAI,'CE REDVICTI0N 1. 5.0 4.2 2. 5.0 2.7 5. 5.0 1.6 10. 5.0 1.1 15. 5.0 0.9 20. 5.0 0.8 30. 6.0 0.8 40. 8.0 0.7 30. 9.9 0.8 75. 1 lee. 9 ).a 100. 19.9 0.8 150. 29.a 0.9 200. 39.8 0.9 250. 49.7 1.0 300. 59.7 1.0 350. 69.6 1.0 2000MF1 COAL-FIRED PLANT PASQUILL-GIFFOP,D D WIND SPEED = 5.0 M/S B A CKGROU;7D VISUAL RANGE = 200. 101 PLUPiF.- V I SL AL DOT-,W vIND ODS^R%%R Rp-.�7G DISTANCE DISTANCE REDUCTION r-CA) ( %) 1. 5.0 3.9 2. 5.0 2.4 5. 3.0 1.4 10. 5.0 1.0 15. 5.0 0.8 20. 5.0 0.7 30. 6.0 0.6 =0. 8.0 0.6 50. 9.9 0.6 75. 14.9 0.6 100. 19.9 0.6 150. 29.a 0.7 2C3. 39.3 0.3 253. 49.7 0.8 300. 59.7 0.9 350. 69.6 0.9 PLUM PLUM CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RAT I O MI CRON E(L*A B,-'.) 0.957 -.026 1.99 0.947 -.023 2.29 0.922 -.025 3.22 0.856 -.029 4.29 0.832 . ©3 2 4.83 0.E74 -.034 5.21 0.8£0 -.033 5.00 0.9,02 -.029 4.21 0.920 -.025 3.4.9 0.952 -.019 2.22 0.971 -.014 1.45 0.939 -.00u 0.64 0.996 -.005 0.30 0.999 -.003 0.14 1.000 -.002 0.03 1.000 -.001 0.04 PLUM, PLUMM COIiTRAL T PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B=") 0.939 -.040 2.53 0.930 -.033 2.75 0.9%4 -.031 3.74 0.875 -.C35 4.94 0. s?5,9 5.60 -.039 5.93 0.8;)i -.C3J 5.90 0.372 -.C33 5.26 0.839 -.032 4.63 0.922 -.026 3.40 0.944 -.022 2.57 0.970 -.016 1.51 0.934 -.011 0.91 0.991 -.003 0.56 0.995 -.005 0.35 0.957 -.005 0.23 282 200011W COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 2.5 MIS BACKGROUND VISUAL RANGE PLUME - DOWNWIND OBSERVER DISTANCE DISTANCE ( 21) ( IT'D 1. 5.0 2. 5.0 5. 5.0 10. 5.0 13. 5.0 20. 5.0 Q0. 6.0 40. 8.0 50. 9.9 75. 1-:.9 100. 19.9 150. 29.8 200. 39.3 250. 49.7 300. 59.7 350. 69.6 2000MW COAL-FIRED PLANT PASQUILL-GIFFORP E WIND SPED = 2.5 MIS BACKGROUT 7D VISUAL RANGE PLUI - DOUTNWIND OBSEPtVEIt DISTANCE DISTANCE 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 4•0. 0.0 50. 9.9 75. 14.9 100. 19.9 150. 29.8 200. 39.8 250. 49.7 300. 59.7 3;,0. 69.6 = 20. KM VISUAL PLUME PLUME RANGE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY (7.) RATIO MICRON E(L*A*B*) 11.4 0.975 -.017 1.85 8.3 0.959 -.023 2.76 6.1 0.950 -.025 3.25 4.3 0.946 -.026 3.44 4.3 0.943 -.027 3.62 4.0 0.9; -.029 3.80 3.9 0.954 -.026 3.05 3.9 0.976 -.018 1.76 4.0 0.9,3 -.013 1.02 3.9 O . G9a -. oc5 0. 28 1.9 1.0-3 -.E02 0.09 0.0 1.0^0 -.0^0 0.01 0.0 I.G1,10 -.000 0.00 0.0 1.G^0 -.000 0.00 0.0 1.0^0 -.OGO 0.00 0.0 1.0103 -.00O 0.00 - 50. KM VISUAL PLUT2. PLUPM RANGE COPTRAST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY ( 7.) RATIO MICRON E(L*A*B-x) 10.3 0.926 -.039 3.84 8.1 0.811,13 -.04.7 5.61 5.4 0.862 -.050 6.53 4.1 0.834 - . 0.30 6.94 3.6 0.8�G -.032 7.32 3.3 0.833 -.054 7.68 3.1 0.8.!9 -.054 7.23 3.2 0.3 2 .043 5.83 3.2 0.910 -.042 4.69 3.4 0.956 -.030 2.58 3.5 0.930 -.030 1.33 3.3 0.996 -.009 0.44 3.6 1.030 -.OG4 0.17 1.9 1.0^3 -.002 0.08 0.5 1.003 -.001 0.04 0.0 1.000 -.00O 0.02 283 2@OON' COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 2.5 MIS BACKGROUIND VISUAL RANGE - 100. KM PLUME- VISUAL PLUME PLUM DOWNWIND OBSERVER RANGE CONTRAST PERCEPT - DISTANCE DISTANCE REDUCTION BLUE -RED AT 0.55 IBILITY ( 0) ( KT•D (%) RAT 10 MICRON E(L*A*B*) 1. 5.0 10.2 0.837 -.061 5.19 2. 5.0 7.5 0.833 -.068 7.35 5. 5.0 5.0 0.8G5 -.068 8.51 10. 5.0 3.7 0.794 -.067 8.93 15. 5.0 3.2 0.734r -.063 9.41 20. 5.0 2.9 0.774 -.070 9.87 30. 6.0 2.6 0.776 -.071 9.91 40. 8.0 2.6 0.831 -.063 9.01 50. 9.9 2.6 0.826 -.065 8.07 75. 14.9 2.8 0.381 -.055 5.87 100. 19.9 2.9 0.922 -.044 4.09 150. 29.8 3.3 0.967 -.030 2.08 200. 39.8 3.5 0.9S7 -.020 1.09 250. 49.7 3.3 0.995 -.013 0.62 300. 59.7 4.0 0.999 -.009 0.36 350. 69.6 4.4 1.000 -.006 0.23 2000MW COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 2.5 MIS BACKGROUT:D VISUAL RANGE = 200. KM PLUME- V I SUAL PLUM PLUPIE DOWNWIND OBSERVER RANGE COHTR4ST PERCEPT= DISTANCE DISTANCE REDUCTION BLUE -RED AT 0.55 IBILITY (101) (101) ( �) RATIO MICRON E(L*A*B*) 1. 5.0 9.4 0.844 -.092 6.46 2. 5.0 6.9 0.737 -.093 6.79 5. 5.0 4.4 0.759 -.037 10.00 10. 5.0 3.2 0.750 -.0332 10.42 15. 5.0 2.8 0.739 - . 00-2 10.94 20. 5.0 2.5 0.723 -.034 11.47 30. 6.0 2.2 0.723 -.036 11.66 40. 8.0 2.1 0.738 -.033 11.45 50. 9.9 2.1 0.755 -.633 10.89 75. 14.9 2.2 0.802 -.077 9.18 100. 19.9 2.2 0.847 -.069 7.39 150. 29.8 2.6 0.903 -.C56 4.93 200. 39.3 2.9 0.945 -.055 3.30 250. 49.7 3.2 0.967 -.037 2.31 300. 59.7 3.5 0.931 -.030 1.59 350. 69.6 3.9 0.989 -.02: 1.14 284 2000NW COAL-FIRED PLANT P4-SQUILL-GIFF011d) E WIND SPEED = 5.0 M/S BACKGROMID VISUAL RANGE PLU•y- Dal-,MW IND OESEM-TR DISTANCE DISTf1110E (121) ( Kri) 1. 5.0 2. 5.0 5. 5.0 10. 5.0 13. 5.0 20. 5.0 30. 6.0 4.0. 8.0 50. 9.9 7.;. 14.9 101. 19.9 150. 29.8 20J. 39.8 2GO. 49.7 300. 59.7 330. 69.6 2000MW COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 5.0 M/S EACKGROUI•tD V I SUAL RANGE PLUIM- DOWNWIND OB-QERZ'ER DISTANCE DISTANCE (1-3-1) (I2D 1. 5.0 2. 5.0 5. 5.0 10. 5.0 13. 5.0 20. 5.0 30. 6.0 40. 6.0 50. 9.9 75. 14.9 100. 19.9 150. 29.8 200. 39.8 250. 49.7 300. 5�.7 350. 69.6 = 20. kM VISUl1. PLUX PLUM R414GE CO14TIlAST PERCEPT- REDUCTIOR BLUE --RED AT 0.55 IBILITY M RATI4) MICIll. 0N E(L*,k*Bx) 6.8 0.937 -.009 1.02 4.6 0.932 -.010 1.22 3.0 0.977 -.011 1.49 2.4 0.9"0 -.013 1.87 2.2 0.965 -.015 2.16 2.1 0.961 -.017 2.38 2.1 0.9G9 -.016 2.00 2.2 0.933 -.011• 1.18 2.2 0.942 -.003 0.68 2.2 0.999 -.003 0.18 1.1 1.030 -.001 0.05 0.0 1.0;0 -.00O 0.01 0.0 1.000 -.000 0.00 0.0 1.0110 -.GCO 0.00 0.0 1.0^0 -.000 0.00 0.0 LOCO -.000 0.00 = 50. IQI V I SU.4L PLUM PLUM R ARGE CONTRAST PERCEPT - REDUCTION BLUEE-RED AT 0.55 IBILITY (?.) MT 10 IIICROil E(L*A*B*) 6.5 0.960 -.023 2.11 4.3 0.949 -.023 2.47 2.7 0.936 -.022 2.97 2.1 0.919 -.CAS 3.72 1.3 0.906 -.C29 4.30 1.7 0.897 -.632 4.73 1.6 0.899 -.033 4.72 1.7 0.920 -.030 3.91 1.6 0.938 -.027 3.13 1.9 0.970 -.018 1.69 1.9 0.987 -.012 0.87 1.9 0.998 -.003 0.24 1.7 1.000 -.002 0.03 0.9 1.0J0 -.001 0.03 0.2 1.000 -.000 0.01 0.0 1.000 -.000 0.01 285 2000MW COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED = 5.0 HIS BACKGROUND VISUAL RANGE = 100. KM PLUME- VISUAL DOWNWIND OB.SERt'ER RANGE DISTANCE DISTANCE REDUCTION ( IiU (lull ( 3 ) 1. 5.0 6.1 2. 5.0 4.0 5. 5.0 2.5 10, 5.0 1.8 15. 5.0 1.6 20. 5.0 1.4 30. 6.0 ..3 40. 8.0 .4 50. 9.9 1.4 75. 14.9 1.5 100. 19.9 1.6 150. 29.8 1.6 200. 39.8 1.6 230. 49.7 1.6 300. 59.7 1.6 350. 69.6 1.5 2000MW COAL-FIRED PLANT PASQUILL-GIFFORD E WIND SPEED 5.0 HIS BACKGROUND VISUAL RANGE = 200. KM PLM- VISUAL DOWNWIND OBSERt1ER RAT;CE DISTANCE DISTANCE REDUCTION 1. 5.0 5.6 2. 5.0 3.7 5. 5.0 2.2 10. 5.0 1.6 15. 5.0 1.4 20. 5.0 1.2 30. 6.0 1.1 40. 8.0 1.1 50. 9.9 1.1 75. 14.9 1.1 iGO. 19.9 1.2 150. 29.8 1.3 200. 39.3 1.3 250. 49.7 1.4 3C0. 59.7 1.4 350. 69.6 1.3 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B*) 0.938 -.037 2.88 0.925 -.033 3.24 0.909 -.031 3.81 0.886 -.034 4.74 0.869 -.033 5.47 0.856 -.041 6.02 0.851 -.043 6.35 0.865 - . 04.2 5.91 0.801 -.040 5.32 0.920 -.033 3.80 0.949 -.026 2.59 0.981 -.016 1.17 0.993 -.009 0.53 0.993 -.605 0.25 1.000 -.003 0.13 1.000 -.002 0.07 PLtTTIME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RAT 10 MICRON E(L*A.*B*) 0.912 -.057 3.65 0.902 -.047 3.91 0.8u7 -.041 4.47 0 . uf52 - . 0 :•3 5.43 0.GT2 -.046 6.31 O.C23 -.043 6.94 0.616 -.C52 7.52 0.823 -.052 7.43 0.834 -.051 7.10 0.869 -.047 5.87 0.901 -.OSO 4.62 0.947 -.029 2.75 0.972 -.021 1.62 0.936 -.015 0.95 0.992 -.010 0.58 0.996 -.037 0.36 2000MW COAL-FIRED PLANT PASQUILL-GIFFORD F WIND SPEED = 2.5 M/S BACKGROLTID V I SU_AL RANGE PLUME- DOI.74WIND OBSERVER DISTANCE DISTANCE ( I21) ( KM) 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 3.0 20. 5.0 30. 6.0 40. 8.0 50. 9.9 75. 14.9 100. 19.9 150. 29.8 200. 39.3 250. 49.7 300. 59.7 350. 69.6 20OOMW COP1.-F 1 P.ED PLANT PASQUILL-GIFFORD F WIND SPEED = 2.5 M/S BACKGRO01D VISUAL RANGE PLUPIE- DOiti^.' WIND OBSERVER DISTANCE DISTANCE ( I3•I) ( HI:) 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 3.0 20. 5.0 30. 6.0 40. 8.0 50. 9.9 75. 14.9 103. 19.9 150. 29.3 200. 39.3 250. 49.7 300. 59.7 350. 69.6 = 20. KM V I SU_AL PLUME PLUME PX4GE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY ( #) RATIO MICRON E(L*A*B*) 15.5 0.967 -.022 2.46 13.3 0.936 -.037 4.35 10.3 0.917 -.047 5.48 8.4 0.915 -.047 5.59 7.5 0.914 -.046 5.60 7.0 0.913 -.046 5.63 6.6 0.937 -.039 4.29 6.9 0.966 -.027 2.42 7.0 0.935 -.019 1.39 7.2 0.998 -.003 0.40 3.0 1.000 -.003 0.15 0.0 1.000 -.000 0.03 0.0 1.000 -.000 0.00 0.0 1.000 -.00O 0.00 0.0 1.000 -.000 0.00 0.0 1.000 -.000 0.00 = 50. KM VISUAL PLUME PLUM RANGE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY (76) R1TI0 MICRON E(L*A*B,:) 14.7 0.903 -.051 5.10 1.2.2 0.821 -.076 8.96 9.1 0.774 -.090 11.33 7.2 0.763 -.0�? 11.55 ` 6.4 0.763 -.033 11.54 5.9 0.766 -.033 11.61 5.6 0.793 -.083 10.42 5.6 0.843 -.072 8.17 5.8 0.831 -.064 6.42 6.2 0.942 -.045 3.55 6.6 0.973 -.032 2.00 7.2 0.9^b -.016 0.71 7.2 I.E^0 -.007 0.31 3.1 1.001 -.00,0 0.15 0.2 1.001 -.002 0.03 0.0 1.001 -.001 0.0e, 287 2000MW COAL. -FIRED PLANT PASQUILL-GIFFORD F WIND SPEED = 2.5 MIS BACKGROU14D VISUAL RANGE = 100. KN PLU12:- VISUAL DOWNWIND OBSERVER RANGE D I STANCE DISTANCE REDUCTION 1. 5.0 13.9 2. 5.0 11.4 5. 5.0 8.3 10. 5.0 6.5 15. 5.0 5.6 20. 5.0 5.2 30. .6.0 4.8 40. 8.0 4.8 50. 9.9 4.8 75. 14.9 5.1 100. 19.9 5.5 150. 29.8 6.2 200. 39.8 6.8 250. 49.7 7.3 300. 59.7 7.6 330. 69.6 8.0 2000MW COAL-FIRED PLANT PA.SQUILL-GIFFORD F WIND SPEED = 2.5 YVS BACKGROUND VISUAL R.4I?,, = 200. KM PLUPC- VISL?AL DOUTNWIND OBSERN'ER RAP'CE DISTANCE DISTAllCE REDUCTIOPt ( KPI) ( 0) ( i. ) 1. 5.0 12.9 2 5.0 10.4 5. 5.0 7.4 10. 5.0 5.7 15. 5.0 5.0 20. 5.0 4.5 30. 6.0 4.1 40. 6.0 4.0 50. 9.9 4.0 75. 14.9 4.1 100. 19.9 4.4 1m0. 29.8 5.0 233. 39.8 5.5 250. 49.7 6.1 300. 59.7 6.5 350. 69.6 7.0 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B*) 0.851 -.030 6.89 0.741 -.106 11.80 0.679 -.120 14.86 0.674 -.117 15.10 0.673 -.114 15.06 0.672 -.113 15.14 0.690 -.110 14.40 0.732 -.104 12.70 0.763 -.09G 11.20 0.841 -.03y 8.17 0.892 - . 07'2 5.94 0.9J3 3.19 0.931 -.036 1.81 0.914 -.025 1.10 0.999 -.017 0.73 1.001 -.012 0.50 PLUPLr.r-- PLUM, CONTIL3ST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO III CRON E(L*A*B*) 0.796 -.113 8.60 0.673 -.141 14.15 0.603 -.150 17.62 0.603 -. 14.2 17.81 0.6015 -.138 17.73 0.60.5 -.13G 17.80 0.616 -.133 17.45. 0.643 -.130 16.37 0.672 -.127 15.36 0.733 -.120 13.00 0.7v6 -.112 10.90 O.665 -.097 7.63 0.917 -.033 5.40 0.949 -.070 3.91 0.970 -.059 2.93 2.27 200OMW COAL-FIRED PLANT PASQUIL L-GIFFOFLD F WIND SPL•£D = 5.0 M/S BACKGROUND VISUAL RANGE PLUPIE- DO' ,"iti III*D OBSZ RVER DISTANCE DISTANCE ( I'.7.1) (ICI) 1. 5.0 2. 5.0 5. 5.0 10. 5.0 15. 5.0 20. 5.0 30. 6.0 40. 8.0 50 9.9 75.. 14.9 103. 19.9 150. 29.8 203. 39.6 250. 49.7 3G0. 59.7 3-0. 69.6 2000MW COAL-FIRED PLANT PASC:UILL-GIFFO;JD F T.'IND SPEED = 5.0 M/S BACKGROUND VISUAL RANGE PLU:a- D71.71jv I ND OBSERVER DISTAIICE DIST.oU,CE (ICI) ( IC -I) 1. 5.0 2. 5.0 5. 5.0 ?0. 5.0 15. 5.0 �0. 5.0 30. 6.0 40. 8.0 50 9.9 75.. 14.9 100. 19.9 150. 29.8 200. 39.8 2.53. 49.7 300. 59.7 �50. 69.6 = 20. KM V I S UAL PLUPM PLUMr, R,'_Ik'GE COINTFul-ST PERCEPT- REDUCTI0H BLUE -RED AT 0.55 IBILITY (%) RATIO MICP,?Ii E(L*A',"B':,) 8.9 0.934 -.012 1.24 6.8 0.975 -.014 1.74 4.7 0.963 -.416 2.03 3.6 0.964 -.017 2.29 3.4 0.960 -.013 2.50 3.2 0.937 -.E20 2.69 3.2 0.963 -.013 2.26 3.3 0.932 -.014 1.35 3.4 0.991 -.010 0.60 3.6 0.999 - . Gold. 0.23 1.7 1.030 -.G02 0.08 0.0 1.0�0 -.000 0.01 0.0 1.0C3 -.000 0.00 0.0 1.000 -.000 0.00 0.0 1.000 -.00O 0.00 0.0 1.000 -.CGG 0.00 = 50. KM VISUAL PLUM PLUME RANGE CONTRAST PERCEPT - REDUCTION BLUE -RED AT 0.55 IBILITY ( 7.) PLAT 10 MICRON E(L*A* B-=) 3.5 0.953 -.02a 2.59 6.3 0.923 -.031 3.54 4.3 0.911 -.033 4.19 3.3 0.902 -.034 4.59 3.0 0.393 -.036 5.00 2.3 0.834 -.033 5.38 2.6 0.837 -.039 5.34 2.7 0.909 -.036 4.49 2.8 () . 9'?8 -.033 3.70 3.1 0.963 -.025 2.19 3.4 0.93: -.01u 1.26 3.7 0.997 -.009 0.44 3.9 1.000 -.004 0.18 1.3 1.030 -.002t 0.03 0.1 1.O00 -.001 0.04 0.0 1.0100 -.000 0.02 KIM 2000N COA-T--FIRED PLANT PASQUILL-GIFFORD F WIND SPEED = 5.0 MSS BACKGROUND VISUAL RANGE = 100. KM PLUPZE- V I SUAL D01'NWIND OESEttITR FLANGE DISTANCE' DISTANCE REDUCTION 1. 5.0 8.0 2. 5.0 5.9 5. 5.0 4.0 10. 5.0 3.0 13. 5•.0 2.6 20. 5.0 2.4 30. 6.0 2.3 40. 8.0 2.3 50. 9.9 2.3 75. 14.9 2.5 100. 19.9 2.8 150. 29.8 3.2 200. 39.8 3.5 230. 49.7 3.7 300. 59.7 3.8 350. 69.6 3.9 2000MW COAL-FIRED PLANT PASQUILL-GIFFOFTJ F WIND SPEED = 5.0 MIS BACKGROUND VISUAL RANGE = 20;1. KM PLUM- VISjT_4L. DOk'NWIND OBSERVLR RANGE DISTANCE DISTAYCE REDUCTION ( I0l) ( IL:) ( % ) 1. 5.0 7.4 2. 5.0 5.4 5. 5.0 3.5 10. 5.0 2.7 15. 5.0 2.3 20. 5.0 2.1 30. 6.0 2.0 40. 8.0 1.9 50. 9.9 1.9 75. 14.9 2.0 103. 19.9 2.2 150. 29.3 2.5 200. 39.8 2.13 25C. 49.7 3.0 30::. 59.7 3.2 351". 69.6 3.4 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*B*) 0.925 -.046 3.55 0.894 -.047 4.65 0.873 -.046 5.41 0.861 5.90 0.849 -.047 6.40 0.838 -.050 6.89 0.832 - . 052 7.24 0.816 -.052 6.83 0.861 -.051 6.32 0.898 -.046 4.97 0.928 -.041 3.76 0.967 -.030 2.06 0.9u7 -.021 1.13 0.995 -.014 0.65 0.999- -.E09 0.40 1.C,30 -.006 0.26 PLUME PLUME CONTRAST PERCEPT - BLUE -RED AT 0.55 IBILITY RATIO MICRON E(L*A*BM) 0.892 -.071 4.52 0.861 -.067 3.63 0.641 -.061 6.38 0.329 -.053 6.68 0.816 - . 039 7. 43 0.804 -.061 7.99 0.792 -.064 8.63 0.796 -.065 8.65 0.804 -.C66 8.49 0.831 -.065 7.74 0.859 -.063 6.78 0.903 -.056 4.90 0.943 -.047 3.44 0.966 -.039 2.41 0.930 -.033 1.72 0.933 -.026 1.27 290 LEGEND: 1-500 MIJE 2-1000 K'!E 3-2000 MHE 20.0 Z C 5.0 W IL 0.0 1.0 00.9 N f Q W 0.8 W, J 100.7 0.6 -0.00 -0. 0" _ -0.0r c -0. 06 -0.06 -0.10 'J -0.12 -0.14 -0.16 20.0 15.0 w j 10.0 w 0 5.0 0.0 I 1 I DOWNWIND DISTANCE (KM) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS C 2•S M/S WIND SPEED 20.0 KM VISUAL RANGE 291 LEGEND: 1-500 MWE 2-1000 MHE 3-2000 MWE 20.0 m 0.9 cc w W 0.8 W J m 0.7 0.6 —0. cc, —0.02 t- —0. 04 co cr —0.06 z 0 —0. 08 a —0.12 —0.14 —0.16 20.0 15.0 W 10.0 J W 0 5.0 0.0 3 3.0 l 1 v l .J 00HNHIND DISTANCE (KM) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS C 2.5 M/S WIND SPEED 50.0 KM VISUAL RANGE 292 LEGEND: 1-500 NNE 2-1000 MWE 3-2000 MWE 20.0 i 5.0 w A. 0.0 1.0 m 0.9 a rc 0.6 d w r 0.7 0.6 -0.00 -0.02 -0.04 n r -0.06 -0.06 -0.10 J a -0.12 -0.14 -0.16 20.0 10.0 5.0 0.0 -9• D 00NNWIN0 DISTANCE (KM) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS C 2.5 M/E� WIND SPEED 100.0 KM VISUAL RANGE 293 LEGEND: 1-500 MWE 2-1000 MWE 3-2000 140E 010.0 0.0 1.0 m 0.9 Q w w 0.8 cc 0.E -0.0[ -0.02 c� -0.OE L -0.1( ° -0.12 -0.14 -0.IE 20.1 LL' 15.0 5.0 0.0 2.0 3. 0 �• 0 DOWNWIND DISTANCE (KM) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS C 2.5 M/S WIND SPEED 200.0 KM VISUAL RANGE 294 LEGEND: 1-500 MWE 2-1000 MWE 3-2000 MWE 20.0 tn 10.0 M 0.0 1.0 m 0.9 r Q w W 0.6 w 0.6 -0.00 -0.02 -0.04 N -0.0S F z u -0.OE -0.10 J -0.12 -0.14 -0.16 20.0 W 15.0 5.0 0.0 DOWNWIND DISTRNCE (KM) VISUAL IMPACTS OF POWER PLANTS OF INOICATEO SIZE STABILITY CLASS C 5.0 M/S WINO SPEED 20.0 KM VISUAL RANGE 295 LEGEND: 1-500 MHE 2-1000 MWE 3-2000 MWE 20.0 z 5.0 w 0.0 1.0 .0 m 0.9 cr w w 0.8 W J m 0.7 0.6 -0.00 -0.02 1. -0.04 w cr -0.06 F -0.08 uj -0.10 J -0.12 -0.14 -0.16 20.0 15.0 w 10.0 J W O 5.0 0.0 3. 0 r. Q DOWNWIND DISTANCE (KM) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS C 5.0 M/S WIND SPEED 50.0 KM VISUAL RANGE 296 LEGEND: 1-500 MWE 2-1000 ME 3-2000 1101E 20.0 0.0 1.0 % 0.9 W 0.6 de W J 0.7 0.6 -0.00 -0.02 H -0.04 N H -0.06 2 u -0.08 W -0.10 J , -0.12 -0.14 -0.16 20. 15. W J 10' W O S. �I'm in 3. .0 V 0 0 0 9.0 2.0 01 2 4 6 10 20 40 60 100 200 DOWNHIND DISTHNUt tRMI VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS C 5.0 M/S WIND SPEED 100.0 KM VISUAL RANGE 297 20.0 15.0 c� c W 0. N 10.0 9" a 0.0 1.0 0 0.9 Q w w 0.8 Ir 0.6 -0.00 -0.02 cr -0.06 z -0.08 0.10 a -0.12 -0.14 -0.16 20.0 W 15.0 5.0 0.0 LEGEND: 1-500 MWE 2-1000 MWE 3-2000 MWE u .0 0 --------------- --1.0 2.0 3.0 2.0 I DOWNWIND DISTANCE (KM) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS C 5.0 M/S WIND SPEED 200.0 KM VISUAL RANGE 298 LEGEND: 1-500 MHE . 2-1000 MWE . 3-2000 MWE . 20.0 Z 15.0 J L n 10.0 A 0.0 1.0 B 0.9 w 0.8 K W D J m 0.7 0.6 -0.00 -0.02 �. -0.04 -0.06 ,d, -0. 08 -0.10 J a -0.12 -0.14 -0.16 20.0 15.0 W cc 10.0 W C 5.0 0.0 1.0 2.0 IOHNWIND DISTANCE tKMJ VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STRBILITY CLASS D 2.5 M/S WIND SPEED 20.0 KM VISUAL RANGE 299 20.0 H 2 a 5.0 W a- 0.0 1.0 m 0.9 f- cr w � 0.8 w J m d.7 O.E -0.00 -0.02 -0. 01 in cr lk: -0. OE z -0.OE -0.IC J a -0.12 -0.1 4 -0.16 20.0 W 15.0 5.0 0.0 LEGEND: 1-SOO MWE 2-1000 MWE 3-2000 MHE 1.0 z.o s.Q MD 3.0 3,0 DOWNWIND OISTRNCE (KM) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS 0 2.5 M/S WIND SPEED 50.0 KM VISUAL RANGE 300 20.0 10.0 S.0 J 0.0 1.0 0.9 N f Q Q m 0.7 -0.02 0.-0.04 -0.06 2 u -0.08 -0.10 J '-0.12 -0.14 -0 .16 20.0 15.0 S.0 0.0 LEGEND: 1-500 MWE 2-1000 MWE 8-2000 ME '2. Q 3.0 3.0 03HNNINO DISTRKE IRK) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS D 2•5 M/S WIND SPEED 100.0 KM VISUAL RANGE 301 LEGEND: 1-500 MWE 2-1000 MWE 3-2000 MILE 20.0 0.0 1.0 1.d m 0.9 Iz w w 0. 6 m 0. f 0.6 —0.00 I— cr u� -0.06 z —0.06 ui —0.10 J � -0.12 -0.14 -0.16 20.0 15.0 W cr 10.0 J W O 5.0 0.0 3.0 2.D �.D DOWNWIND DISTANCE (KM) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS D 2.5 M/S WIND SPEED 200.0 KM VISUAL RANGE 302 LEGEND: 1-500 MWE 2-1000 MWE 3-2000 MWE 20.0 0.0 1.0 B 0.9 M Q Q� W 0.8 W n J m 0.7 0.6 -0.00 -0.02 F . -0.04 >; -0.10 JJ i' -0.12 -0.14 -0.16 20.0 10.0 wu m 5.0 0.0 [JWNWIND DISTRNGE LRr» VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS 0 5.0 M/S WIND SPEED 303 20.0 KM VISUAL RANGE 20.0 z m 15.0 L) m 0 w ce 10.0 0.0 1.0 m 0.9 N Q w W 0.8 0° 0.7 0.6 —0.00 —0.02 $.- —0.04 vn cr —0.06 z a, —0.08 i —0.10 -1 °' —0. 12 —0.14 —0.16 20.0 w 15.0 5.0 0. Ll LEGEND: 1-500 MWE 2-1000 MHE 3-2030 MWE 3.0 DOWNWIND DISTANCE (KM) VISUA! IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS D 5.0 M/S WIND SPEED 50.0 KM VISUAL RANGE 304 LEGEND: 1-500 MWE 2-1000 MWE 3-2000 MWE 20.0 z F 15.0 10.0 M 3w 0.0 1.0 O 0.9 H ¢ uuo 0.8 ¢ 0.6 -0.00 -0.02 -0.04 U1 oe -0.08 0.10 -0.14 -0.16 20.0 15.0 W J 10.0 W O -0 IU • DOWNWIND DISTRNCE thm) VISUAL IMPACTS OF POWEF PLANTS OF INDICATED SIZE �'~ STABILITY CLASS D S . 0 M/S WIND SPEED 100.0 KM VISUAL RANGE 305 LEGEND: 1-500 NNE 20.0 H z Ge 5.0 W A. 0.0 1.0 m 0.9 a. a w W 0.8 °D 0.7 0.8 -0.00 -0.02 �n ie -0.08 z -0.10 J d -0.12 -0.14 -0.18 20.0 15.0 W F 10.0 .J W O 5.0 0.0 . 2-1000 ME . 9-2000 NNE 11 0 2.0 ? 3,0 .0 00"NNIND DISTRNCE IKMI VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS D 5.0 M/S WINO SPEED 200.6 KM VISUAL RANGE 306 20.0 0.0 1.0 a 0.9 N r Q a w 0.8 a W 7 a m 0.7 0.6 -0.00 -0.02 �. -0.04 a -0.12 -0.14 -0.16 20.0 15.0 5.0 LEGEND: 1-500 MWE 2-1000 MWE 9-2000 mw- . 3.0 I.0 z.a 3.0 0.01 2 4 6 10 20 40 60 100 200 OQWNWIND ulsim t.t tnrl) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS E 2.5 M/S WIND SPEED 20.0 KM VISUAL RANGE 307 LEGEND: 1-500 MWE 20.0. 0.0 1.0 0 0.9 cr w W o.s 0.6 -0.00 -0.02 I.- cn cr f- -0.06 z -0.08 s -0.10 _ J °' -0. 12 w -0.14 -0.16 20.0 15.0 5.0 0.0 . 2-1000 MWE . 3-2000 MWE • I.0 2.0 o 2.0 1.0 3.0 3.0 3.4 DONNHIND DISTANCE (KM) VISURL IMPACTS OF POWER PLRNTS OF INDICATED SIZE STABILITY CLRSS E 2.5 M/S WIND SPEED 50.0 KM VISURL RRNGE 308 LEGEND: 1-500 MWE 2-1000 MWE 3-2000 MWE 20.0 r z 5.0 W L 0.0 1.0 m 0.9 N Q W 0.8 w 0.6 -0.00 -0.02 .0.04 u -0.08 -0.10 J d -0.12 -0.14 -0.16 20.0 15.0 W J 10.0 W c 5.0 0.0 3.0 I.0 2.0 1.0 2.0 3.0 1.0 2.0 3.0 3.0 2.d !.0 1 2 +! 6 10 20 DOWNWIND DISTANCE (KM) 40 6 1 0 200 VISUAL IMPACTS OF POWER PLRNTS OF INDICRTEO SIZE STRBILITY CLRSS E 2.5 M/S WIND SPEED 100.0 KM VISUAL RRNGE :09 LEGEND: 1-500 MWE 20.0. -- z 5.0 w a- 0.1 1.� m 0.9 cr w 0.8 w m 0.7 0.6 -0.00 -0.02 r -0.04 N a -0.06 z - 0.06 -3.10 J -0. 12 -0. 14 -0.16 20.0 w 15.0 5.0 0.0 . 2-1000 MWE . 3-2000 MWE 1.0 2.0 1.0 2.0 2.0 1.Q -3.Q DOWNWIND DISTANCE (KM) VISUAL_ IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILI7Y CLASS E 2.5 M/S WIND SPEED 200.0 KM VISUAL RANGE 310 LEGEND: 1-500 ME 2-1000 MWE . 3-2000 MHE . 20.0 115.0 0.0 1.0 O 0.9 M Q W 0.8 cr W J 0.7 0.6 -0.00 -0.02 N -0. 04 N -0.06 t -0.08 -0.10 J -0.12 -0.14 -0.16 20.0 15.0 W j 10.0 W O 5.0 0.0 1.0 3.0 I DOHNNIND DISTHNCE lKMJ VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS E 5.0 M/S WIND SPEED 20.0 KV VISUAL RANGE 311 20.0 10.0 M 0 0 1.0 m 0.9 F- W 0.8 z W J m 0.7 0.E -0. cc -0.02 1- -0.01 to cr 0. OE z '9 -0. OE Li -0.10 s -0.12 -0.14 -0.16 20.0 to 15.0 5.0 0.0 LEGEND: 1-500 MUE 2-1000 MOE 3-2000 MHE 1.0 2.0 3.0 3.0 .0 'OHNNIND DISTANCE (KMJ VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS E 5.0 M/S WIND SPEED 50.0 KM VISUAL RANGE 312 LEGEND: 1-500 M11E 2-1000 MWE 3-2000 MWE 20.0 f. 5.0 W 96 0.0 1.0 m 0.9 W 0.8 m 0.7 0.6 -0.00 -0.02 F -0.04 rn -0.06 z u -0.08 x -0.10 J -0.12 -0.14 -0.16 20.0 15.0 W 5.0 0.0 1.0 _ g,4 1.0 1 2 4 6 10 20 DOWNWIND DISTRNCE�(KM140 2Uo VISUAL IMPACTS OF POWER PLANTS OF INDICATEC SIZE STABILITY CLASS E 5.0 M/S WIND SPEED 100.0 KM VISUAL RANGE 313 LEGEND: 1-500 MWE 20.0. 10.0 0.0 1.0 00.9 M Q w W 0.8 m 0.7 0.6 —0.00 —0.02 -o.a4 cc -0.06 z 0 -0.06 W —0.10 J � -0.12 W -0.14 -0.16 20.0 15.0 5.0 0.0 . 2-1000 MWE . 3-2000 MWE . 1.0 2.0 3,0 1.0 3.a q9 3.0 DOWNWIND DISTRNCE (KM) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS E 5.0 M/S WIND SPEED 200.0 KM VISUAL RANGE 314 LEGEND: 1-500 MWE 2-1000 MHE 3-2000 MWE 20.0 0.0 1.0 m 0.9 M R W 0.6 0.6 -0.00 -0.02 F -0. 04 u -0.06 w 1 -0.10 J d -0.12 -0.14 -0.16 20.0 15.0 L 5.0 0.0 2.0 1.0 .0 1.0 2.a 3.4 1.0 2.0 3.0 3.0 2.0 1.0 1 2 4 10 20 40 60 100 200 DOWNNINU UJbJMWLC inni VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS F 2.5 M/S WIND SPEED 20.0 KM VISUAL RANGE 315- LEGEND: 1-500 MWE 20. 0 r----- 0.0 1.0 m 0.9 cc te w 0.8 03 0.7 O.E —0.OL —0. Ml! —0.04 M cc —O.OE 1- Z —O.OE bi —0. 10 J —0.12 —0.14 —0.16 20.0 15.0 S. 0 0.0 2-1000 MWE . 3-2000 MWE 1.0 1.0 1.0 1E c 9.p 3.0 DOHNWIND DISTANCE (KM) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS F 2.5 M/S WIND SPEED 50.0 KM VISUAL RANGE 316 LEGEND: 1-500 MWE 2-1000 MHE . 3-2090 MWE . 20.0 f. Z of 5.0 W A. 0.0 1.0 m 0.9 M Q le W 0.0 w W n J 00.7 0.6 -0.00 -0.02 -0.04 u -0.08 o. --0.12 -0.14 -0.16 20.0 15.0 W J 10.0 W O 5.0 0.0 1.0 1.0 2.0 3.0 Dc r1NNIN0 DISTANCE Mi) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS F 2.5 M/S WIND SPEED 100.0 KM VISUAL RANGE 317 LEGEND: 1-500 MWE 2-1000 MHE 3-2000 MWE 20.0 10.0 H x 5.0 W d 0.0 1.0 0 0. 9 a w W 0.6 m 0.7 0.6 -0.00 -0.02 cr -0.06 x -0.06 bi -0.10 J a -0.12 -0.14 -0.16 20.0 15. W ��m 0. 1.0 1.0 3. 0 2.0 .0 .0 r,J3.0 VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS F 2.5 M/S WIND SPEED 200.0 KM VISUAL RANGE 318 LEGEND: 1-500 MWE 2-1000 MWE 3-2000 MHE 20.0 Iw 15.0 0.0 1.0 m 0.9 W 0.B w W J m 0.7 0.6 -0.00 -0.02 H '0.04 tll -0.06 H t U '0.08 0.10 J 0.12 -0.14 -0.16 20.0 W 15.0 5.0 0.0 .0 3. .0 D@WNN1N0 0I5TRNLt MR) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS F 5.0 M/S WIND SPEED 310 20.0 KM VISUAL RANGE LEGEND: 1-500 MWE 2-1000 MHE 3-2000 MWE 20.0 z m 15.0 U O w !- z I 5.0 W CL 0.0 1.0 m 0.9 a z W 0.8 0.6 -0.00 -0.0 F- -0.04 cn cr -0.06 z coil -0.08 -0.10 J a -0.12 -0.14 -0.16 20.0 W 15.0 5.0 0.0 3.0 1.0 2.0 1.0 1.0 Z. 0 2. 3•0 .0 DO-INHIND DISTANCE (KM) VISURL IMPACTS OF POWER 'LANTS OF INDICATED SIZE STABILITY CLRSS F 5.0 M/S WIND SPEED 320 50.0 KM VISURL RRNGE LEGEND: 1-500 MWE 2-1000 MWE 3-2000 MWE 20.0 0.0 1.0 m 0.9 M Cc w W 0.8 0.6 -0.00 -0.02 i_ -0.04 n -0.06 11-0. 08 IL -0.10 J -0.12 -0.14 -0.16 20.0 15.0 W 5.0 0.0 1 ismiffil 1.0 _ 2 • Q �� 3.0 1.0 2.0 9.0 .0 1.0 g.0 upliNN1NU U101MR6L mr- VISUAL IMPRCTS OF POWER PLANTS OF INDICATED SIZE STRBILITY CLASS F 5.0 M/S WIND SPEED 100.0 KM VI SURL RANGE 321 LEGEND: 1-500 MWE 2-1000 MWE 3-2000 MIT . 20.0 z m 15.0 u c W w cn 10.0 M z uw 5.0 w a- 0.0 1.0 m 0.9 cc w S 0.8 W J 0° 0.7 0.6 -0.00 -0.02 �- -0.04 En ad -0.06 f- z m -0.08 -0.10 J °' -0.12 -0.14 -0.16 20.0 15. Cl W 0.0' 3.a I.0 2.p 3.0 1.0 DOWNWIND DISTRNCE (KM) VISUAL IMPACTS OF POWER PLANTS OF INDICATED SIZE STABILITY CLASS F 5.0 MIS WIND SPEED 200.0 KM VISUAL RANGE 322 APPENDIX E TWO EXAMPLE APPLICATIONS OF THE LEVEL-1 AND LEVEL-2 ANALYSES E.1 EXAMPLE 1--COAL-FIRED POWER PLANT E.1.1 Level-1 Analysis This example is based on a hypothetical coal-fired power plant that has been proposed for a site appro;:imately 70 km from a class I PSD area. The emission rates for thiS, hypothetical power plant are projected to be 25 g/s of particulates, 380 1/sec of nitrogen oxides (as NO2), and 120 g/sec of sulfur dioxide. Figure E-1 shows the relative locations of the proposed site and the class I area. The Federal Land Manager has identified the view toward the mountains to the west as integral to the visitors' experience of the class I area. The discussion below demon- strates the way in which potential visibility impairment in this situation would be evaluated with the level-1 procedure. The level-1 procedure stEps are carried out as follows: 1, P = 2.0 x 108 x = 60 km* ix cZF (60 km) = 83 m p = 4.0 x 104 2. Tpart = 1.0 x 10-6 - P - Qpart TN02 = 1.7 x 10-7 - P - QNOx * Distance from site to closest point of impact, which is the vista to the west. P_? w N PROPOSED POWER PLANT LOCATION 0 10 20 3�4 0 / �( Scale in kilometers M CLASS I AREA Figure E-1. Relative locations of the proposed power plant and class 1 area for example 1. p = 4.0 x 104 Opart = 25 g/s = 2.16 MT/day QNOx = 380 g/s = 32.8 MT/day Tpart. = 0.0864 TN02 = 0.223 3. rv0 = 170 km (The proposed site is in the west -central United States.) 4. Taerosol = (1.06 x 10-5) • rvO - (Qpart + 1.31 QS02) rvO = 170 km Qpart = 2.16 MT/day OS02 = 120 g/s = 10.368 MT/day Taerosol = 0.0284 TN02 5. C1 = - Tpart + TNO 1 - exp(- Tpart TN02} exp(-0.78 x/rv0) 2 C2 = 1 - + �- exp(- part - TNO) exp(-1.56 x/rv0) 1 2 C3 = 0.368 1 - exp(-Taerosol) 0 325 TN02 = 0.223 Tpart = .0.0864 x = 60 km rvo = 170 km Taerosol = 0.02837 C1 = -0.146 C2 = 0.0814 C3 = 0.0103 6. The absolute valve of C1 is greater than 0.10. Therefore, a level-2 analysis is indicated. Atmospheric discoloration due to NO2 is expected to be the most serious problem. E.1.2 Level-2 Analysis The design parameters for the proposed power plant are: Stack height Stack inside diameter Stack gas velocity Stack temperature Particulate emissions rate NOx emissions rate (as NO2): Sox emissions rate (as S02): Site elevation hstack = 150 m 0=8m Vs = 15 m/s Ts = 350°K Qpart = 25 g/s = 2.16 MT/day QNOx = 380 g/s = 32.8 MT/day = QS02 120 g/s = 10.4 MT/day Zsite= 940 m MSL 326 E.1.2.1 Calculating Terrain Effects on Plume Transport The level-2 analysis proceeds as described in the text. First, the potential for interference by terrain features on plume trajectories is identified by comparison with effective stack height. The equation given for dh in the text, ;rah = 1.6 - F1/3 (3.5 x*) 213 - u-1 reduces to: dh = 121.4 F3/4 - u-1 -1 t38.7 F3 5 u where, as before, for F < 55 m4s-3 for F > 55 m4s-3 F _ .V 1 _ Tambient g I Tstack - vs w d 2 hstack = 150 m u=5m/s vs = 15 m/s d=8m Tambient 10°C = 283-K Tstack = 3500K g = 9.8 m/s2 15m/s -3.14 - 8 2 m 2 4 327 V = 754 m3/s F = (9.8 m/s2)(754 m3/s) 1 _ 28303.14 K F = 450 m4/s3 eh = 38.7(450)3/5 5 eh=302m H=150m+302m H=452m Zblock = Zsite + H + 500 m Zblock = 940 m + 452 m + 500 m Zblock = 1892 m Figure E-2 shows the area above Zblock in the vicinity of the class I area and the proposed power plant, along with trajectories affecting visibility in the class I area. Figure E-3 shows terrain elevation plots for several lines of sight from within the class I area. E.1.2.2 Estimating Worst -Case Meteorological and Ambient Conditions Worst -case conditions !or plume discoloration --To characterize worst - case meteorological conditions, we obtained meteorological data from an airport 100 km west of the proposed power plant. Although the intervening terrain is not flat, we judged that the 850 mb wind and stability data are the best available data source. For the trajectory passing to the north- west of the class I area, we tabulated winds from the southwest and west- southwest for both morning and afternoon soundings. From these tabula- 328 PLUME TRAJECTORIES 0 10 20 310 / 4� Scale in kilometers TERRAIN ABOVE Zblock CLASS I AREA Figure E-2. Significant terrain features and possible plume trajectories. VISITORS' CENTER RIVER 70 60 50 40 30 20 10 0 Distance (km) (a) View 1: To the vest from Jisitors' Center (A = 270°) W VISITORS' CENTER- _ RIVER---,, 70 60 50 40 30 20 10 1 Distance (kn) (b) View 2: To the west-northwest front Visitors' Center (A = 292.50) VISITORS' CENTER—",,, RIVER 0 50 40 30 20 10 Distance (km) (c) View 3: To the south-southeast from Visitors' Center (A = 135°) Figure E-3. Terrain elevation plots. 330 tions, a frequency of occurrence (table E-1) was developed. The cumula- tive frequency entries show that on three to four days per year conditions with azu values of 322 m2/s_(E stability, 2 m/s) can be expected. Note that the bulk of the contribution t) the cumulative frequency (0.9% out of 1.0%) represents the 1200 GMT E,2 dispersion conditions. This corresponds to approximately 5 a.m. LST. Note also that the afternoon sounding fre- quency of E,2 dispersion conditions was relatively high (0.6 percent, or about two days per year). Worst -case conditions for general haze* --Because of time and resource considerations, we decided to rely initially on Holzworth (1972) for the necessary data for the determination of episode frequency. A large scale map was obtained, on which circles of radii of integer multiples of 173 km (transport limit per 2 m/s of wind speed) were drawn, centered on the site of the proposed power plant. Class I areas were marked, and the wind sec- tors associated with transport to each area were noted, as shown in figure E-4. From this figure and the two -day -episode data for mixing height and wind speed in Holzworth (1972) (figures 51 through 62),t table E-2 was constructed. The worksheet i,1 figure E-5 shows the extraction of the actual frequency of specific Sri nd speeds and mixing depths for second -and - later episode days from the cumulative data presented in Holzworth. The four -day -per -year uHm value is 4000 m2/s. Note that the principal contri- bution to the frequency of occurrence of this condition derives from a high incidence of greater -than -two-day episodes of Hm between 500 and 1000 m and u between 2 and 4 n/s. This observation is confirmed by the five -day -episode data in figu -e 65 of Holzworth (1972). which show eight episodes lasting a total of 6i days for H < 1000 m and u < 4 m/s. * Note that since C3 was less than 0.1, we could have eliminated this step. However, for purposes of illustration this step is shown. t The numerical values chosen here assume that Grand Junction, Colorado data best characterize the conditions affecting our hypothetical power plant. 331 TABLE E-1. FREQUENCY OF OCCURRENCE OF SW AND WSW WINDS BY DISPERSION CONDITION AND TIME OF DAY * Cumulative Dispersion Transport Time Time of Day Frequency Frequency Condition 2u (m /s) (hrs) OOZ 12Z W W F, 1 03 33 0 0 N/A N/At E, 1 161 33 0 0 N/A N/At D, 1 353 33 0 0 N/A N/A F, 2 166 11 0.1 0 0.1 0.1 E, 2 322 11 0.6 0.9 0.9 1.0 D, 2 706 11 1.6 0.8 1.6 2.6 F, 3 249 7 0 0 0 2.6 E, 3 483 7 0.6 1.4 1.4 4.0 F, 4 332 5 0 0 0 4.0 D, 3 1060 7 3.4 1.2 3.4 7.4 F, 5 415 4 0 0.1 0.1 7.5 E, 4 644 5 0.4 1.2 1.2 8.7 D, 4 1410 5 2.4 1.5 2.4 11.1 F, 6 498 4 0 0 0 11.1 E, 5 805 4 0.2 1.8 1.8 12.9 * OOZ refers to midnight Greenwich mean time (GMT) and 12Z to noon GMT. t Persistence of stable meteorological conditions for over 12 hours is not con- sidered likely. Therefore, conditions requiring greater than 12-hour trans- port time are included in the cumulative frequency computation, but would not be selected as representative of the 111-percentile event." 332 LEGEND O PROPOSED POWER PLANT SITE +SE = CLASS I AREA LOCATION, AND WIND SECTOR THAT RESULTS IN TRANSPORT FROM PROPOSED SOURCE .. Figure E-4. Class I areas within 48-hour transport range at wind speeds up to 8 m/s. 333 TABLE E-2. FREQUENCY OF EPISODE DAYS BY MIXING DEPTH AND WIND SPEED Number of Occurrences f2+t Affecting Class I Area (Day 2+ fre- Sectors with Sectors per Year u H quency per Class I Areas u, Hm (m2/s) five years) (ns) f§ Cumulative 21 500 1000 10 1 0.25 0.25 2, 1000 2000 3 1 0.075 0.325 4, 500 2000 15 3 1.125 1.45 2, 1500 3000 1 1 0.025 1.475 6, 500 3000 1 3 0.075 1.55 2, 2000 4000 0 1 0 1.55 4, 1000 4000 72 3 5.4 6.95 4, 1500 6000 49 3 3.675 10.625 6, 1000 6000 25 3 1.875 12.5 4, 2000 8000 23 3 1.725 14.225 6, 1500 9000 57 3 4.275 18.5 6, 2000 12000 37 3 2.775 21.275 * Example based on Grand Junction, Colorado. t From frequency worksheet shown in figure E-5. § f = f2+ - ns = Class 1 sector impact days 1� year 334 5-year Cumulative (i.e., # < u, < H) No. of Episodes No. of 2nd and Later Days Lasting at Least No. of No. of 2nd for Specific Conditions 2 Days Epis de Days and Later Days (from matrix below) (u, H) _ (fe) ?fd) (fd-fe) (f2+) 29 500 7 17 10 10 49 500 12 37 25 15 69 500 12 38 26 1 29 1000 9 22 13 3 49 1000 29 129 100 72 61 1000 40 166 126 25 29 1500 10 24 14 1 49 1500 43 193 150 49 6, 1500 64 297 233 57 29 2000 10 24 14 0 4, 2000 51 224 173 23 6, 2000 72 365 293 37 4-6 2-4 a 0-2 26 126 233 293 (•26 25) 25 (-126-100-1. 57 (■233-126-49-1. 37 (■293-233-23-0, pr or 126-26-72-3) or 233-150-25-1) 293-173-57-25-1) 3rd 6th gth 12th 25 100 Ro 173 15 72 (-100-25-3. 4`- (■150-10-1. or 23 (-173-150-0 or or 100-13-15) 150-14-7. 15) 173-14-49-72-15) 2nd 5th 6th 11th 10 13 14 14 10 (base case) 3 (-13-10) (-1, 3) u (-14-14) 1st 4th 7th loth 0-500 500-10D0 1000-1500 1500-2000 N (a) 3 :d Order of--' calculating f2+ Calculation of f2+ (shown only for example) Sum = 293 = fd (69 2000) - fe (6, 2000) LEGEND F Total number of second and later episode days with u and HS stated values Number of second and later days within stated u and H ranges Figure E-5. Worksheet for the calculation of windspeed and mixing depth joint frequency distribution 335 Background Ozone Concentration --According to the "W" notation in figures 51 through 62 in Holzworth (1972), limited mixing episodes occur predominantly during winter months in the vicinity of Grand Junction, Colorado. Also, in the same reference, table B-1 gives seasonal mean mix- ing depths and wind speeds. According to this table, the uH value by season is most limiting for winter (uH = 3333, 19448, 22981, and 9011 m2/s, respectively, for winter, spring, summer, and autumn). Therefore, in the absence of any other data for ozone aloft, a conservative winter median ozone estimate of 50 ppb (0.05 ppm) was taken from figure 19 of the text. Background Visual Range- - Tel ephotometer data for several months are available, and we have interpreted them as indicating a median rv0 of 140 km; however, this data set is relatively small. Therefore, the more con- servative estimate of 170 km from figure 13 of the text was chosen for the initial level-2 analysis, based on our recognition that the analysis can be revised as more telephotometer data are generated. E.1.2.3 Calculation of Worst -case Visual Impacts The level-2 hand calcula-..ion procedure is demonstrated in this example. A comparison with the results obtained from reference tables and figures appears at the end of this example. Determining plume -observer -object -sun geometry --Figure E-6 shows plume -observer orientations corresponding to the terrain elevation plots of figure E-3. Plan views of assumed geometries are shown in figures E-7 and E-8. From these figures, the following angles are determined: Azimuth: Al = 270 A2 = 212.5 A3 = 157.5 336 W W V Figure E-6. Observer -plume orientations. VIEW i ro 1 = 55 k w w 00 Figure E-7. Plan view of assumed geometries for views l and 2. w w Figure E-8. Plan view of assumed geometry for view 3. Angle to plume centerline: a1 = 36 ° a2 = 58.5° a3 = 99 ° We chose these lines of sight as the principal vistas for analysis because of the steep terrain and resulting obstructions surrounding the class I area. Therefore, rather than computing scattering angles for a = 30 % 45°9 600, 90°, 120°, 135°, and 1500 for both plume centerlines, we chose to study azimuths including the three principal vistas plus three flanking lines of sight for each plume trajectory. Specifically, for the plume trajectory to the northwest of the class I area, azimuths corresponding to a = 30% 450, and 900 are designated A4, A5, and A6. For the plume tra- jectory passing to the south, azimuths A7, A8, and A9 correspond to a values of 900, 120 % and 135°. Thus, we computed azimuths for views 1 through 3 as follows: Traj.ectory for views 1 and 2: a4 = 30 ° A4 = 264 ° a5 = 45 ° A5 = 279 ° a6 = 90° A6 = 324° Trajectory for view 3: a7 = 900 + A7 = 166.50 % = 1200 + A8 = 136.50 ag = 135° + A9 = 121.50 We computed scattering angles for three scenarios corresponding to m)rning, midday, and late afternoon in early winter (December 21, Julian date 355). Values calculated for these scenarios are subscripted M, N, and A, respectively, in the calculations below: 340 cos ei j = -cos d sin � cos Ai cos Hj + cos d sin Ai sin Hj + sin d cos # cos Ai i=1,2,3 j = M , N , A a = 23.45 sin [3600 284 + n n = 355 f = latitude = 39' N HM = 45° (for 9 a.m. ) HN = 0° (for noon) HA = -60' (for 4 p.m.) Al = 270° A2 = 292.5° A3 = 157.5° A4 = 264° A5 = 279° A6 = 324° A7 = 166.5° A8 = 136.5' A9 = 121.50 d = 23.45 Sin 3600 (284 + 355 = ?3.45 sin (270.20) a =-23.45° cos elm = -(cos - 23.45°) (sin 39°) (cos 270°) (cos 45') + (cos - 23.45°) (sin 270°) (sin 450) - (sin-23.450) (cos 390) (cos 2700) cos e1M =-0.6487 91M = 1300 341 Similarly, eij values are derived for the other azimuth/time-of-day pairs, as shown in table E-3. E.1.3 Calculation of Plume Optical Depth The plume flux of scattering coefficient, Qscat-part is calculated with a particle -size distribution different from those used in the level-1 analysis. The values chosen here are expected to more accurately charac- terize emissions from this proposed project. Specifically: 1160 Qpart bscat /V) Qscat-part = a Qpart = 2.16 MT/day P = 2 g/cm3 DG = 1 un cg = 2 bscat/V = 0.05 (from figure 24) Qscat-part 10.55 wn _ 63 m2 /s For the determination of NOx concentration, we have 6.17 QNO x NO x = Zux 342 w w TABLE E-3. VALUES OF eij (A;i) 1 2 3 4 5 6 7 8 9 (270') (297.5') (157.5') (264') (279') (324') (166.5') (136.5') (121.5') M(45') 130 151 24 125 139 164 32 15 22 N(0') 90 110 35 85 98 136 30 50 62 A(60') 37 60 76 32 46 91 67 97 111 QNOx = 32.8 MT/day Qz u = 322 m2/s (from table E-1) x = 60 km NOx = 0.0105 ppm As the background ozone concentration (0.05 ppm) is greater than this cal- culated value for [NOx], we may assume complete conversion of NO to NO2. Thus: [NO2]1 x = 60 = [NOX]jx = 60 = 0.0105 PPm Although we are concerned about nighttime stable transport of pollutants, as a check on the extent to which we may be overestimating [NO2] during daylight hours, we have also calculated [NO2] using the alternate formula- tion. [NO2] = 0.5 [NO x] + h + j - ([NOx] + h + j)2 - 4 [NO x] h 1 1/2 Values of Zs of 90 % 75% 45° and 0° are computed, yielding the following: ZS [NO2] 900 0.0105 ppm 750 0.0093 450 0.0080 0° 0.0077 Thus, even with the sun directly overhead (which would not occur for the latitude and season of concern), there is a relatively small difference in projected [NO2]. For the remainder of the level-2 analysis, therefore, we will continue to use the more conservative value of 0.0105 ppm. 344 The optical thickness of the plume resulting from NO2 is calculated for A = 0.40, 0.55, and 0.70 un, using the equation: TN02 = 0.398 [N021 • x - (babs/ppm) [N021 = 0.0105 ppm x = 60 km 1.71 for a = 0.40 um (babs/ppm) = 0.31 for A = 0.55 0.017 for a = 0.70 "NO2 = 0.429 at a = Q .4 un tNO2 = 0.073 at a = 0.55 w TN02 = 0.00426 at a = 0.7 on Light scattering by sulfate aerosol is calculated under the 40 percent relative humidity assumption for the western United States. Thus, 43.4 kf QSO Qscat-SO4 = k + - RH 20 1-exp-0.48(kf + kd f d )] kd = vd/Hm - 3600 kf = 0.1 %/hr (winter) Vd = 0.5 cm/s Hm = 2000 m* QS02 = 10.4 MT/day RH = 40% * Note from table E-2 that either 1000 or 2000 m could be assumed for Hm. In this equation, the higher value of Hm yields the most conservative result. Therefore, 2000 m has been used. 345 Therefore, and k' = kf + kd = 1.0%/hour Qscat-SO 4 a 0.55 un = 28.7 m2/s Next, Qscat wavelength dependence is determined via the equation -n(DG, 9) Qscat ` Qscat 10.55 vm . �''' which is based on the proportionality of Qscat and bscat- Thus, (2.4,__)-n (1,2) Qscat-part lx=0.4 = Qscat-part IX=0.55 5 Qscat-part lx=0.4 = 67 Similarly, Qscat-part IX=0.7 = 60 n (1,2) = 0.2 (from table 4) Qscat-partly _ 2 0.55 63 m /s 346 For Qscat-SO41, the size distribution has an assumed mass median diameter of 0.3 un and ag of 2. Thus, 0.4 " n(0.3,2) Qscat-SO4 � 0.4 - Qscat-SO M.3v un 4 a=0.55 Qscat-SO 4 a 0.55 = 28.7 m2/s n (0.3,2) = 1.6 Qscat-SO4 a = 0.4 = 47.8 m2/s Similarly, Qscat-SO 4 1 a 0.7 = 19.5 m2 A Optical thickness (T) calculations are made using the equation and T _ Q scat -part part (2(2v)�l a u z Qscat-part + Qscat-SO4 jaerosol = u m ' where azu = 322 m2/s and uHm = 4000 m 2 A . 347 Below are the tabulated values for T for particulates, general haze, and NO2 shown as a function of wavelength. 0.4tm 0.55 on 0.70ym Tpart 0.083 0.078 0.074 Taerosol ).0287 0.0229 0.0199 TN02 0.429 0.078 0.00426 E.1.4 Phase Function Calculations The wavelength, scattering angle, and particle -size -dependent phase function calculations are performed next. bext � a = 0.55 un) = 3r912 v0 rv0 = 170 km bext(X = 0.55) = 0.023 km-1 bscat(X = 0.55 in) = 0.95 bext bscat(' = 0.55) = 0.022 km-1 348 bap = 0.05 bext bap = 0.0012 km-1 bR(A = 0.55) = (11.62 x 10-6m-1) exp - Z 80000 Z=940m bR(X = 0.55) = 1.0 x 10-5 m-1 = 0.010 km 1 bsp(a = 0.55) = bscat bR bsp(a = 0.55) = 0.012 km-1 The attribution of bsp to coarse and fine particles in 1/3 : 2/3 pro- portions gives: bsp-coarse = 0.004 km- bsp-submicron = 0.008 km -1 Wavelength dependence is calculated as before, using: -n bpsp ( A) = b(a x s0.55 on) (0.55� 349 where ncoarse = 0 nsubmicron = 1.6 nRayleigh = 4.1 naverage = 0.2 The wavelength -specific bsp values thus calculated are shown in table E-4 along with phase functions calculated for Rayleigh scattering according to p(e) = 0.75 [1 + cos20] for all a and extracted from appendix B for Mie scattering by coarse (DG = 6 tim) and fine (DG = 0.3 wn) mode particles. Average p(a,0) values are calculated according to P(a,0)1 = lbackground 1] s p Rayleigh, coarse, fine sp Rayleigh, coarse, fine Plume phase function values have also been taken from appendix B, for DG=1 vmand og=2. 350 TABLE E-4. PHASE FUNCTIONS AND SCATTERING COEFFICIENTS FOR BACKGROUND AND PLUME Phase Function p( a,e) for Indicated 9 Scattering Component a (ur,) bscat (km-1) 360 90' 1300 BACKGROUND Rayleigh Scattering Due to air molecules 0.40 0.037 at site elevation 0.55 0.01 1.24 0.75 1.06 (n = 4.1) 0.70 0.0037 Mie Scattering Submicron aerosol 0.40 0.013 2.87 0.276 0.157 DG = 0.3 um 0.55 0.008 2.90 0.318 0.189 Qg = 2.0 0.70 0.005 2.88 0.357 0.211 (n = 1.6) Mie Scattering Coarse aerosol 0.40 0.004 1.56 0.147 0.0552 DG = 6 um 0.55 0.004 1.44 0.161 0.0529 cg = 2.0 0.70 0.004 1.61 0.167 0.0825 (n=0) Total (average) 0.40 0.054 1.66 0.591 0.768 0.55 0.022 1.88 0.486 0.560 0.70 0.013 1.96 0.402 0.408 PLUME DG = 1 um 0.40 2.22 0.203 0.159 og = 2 0.55 2.45 0.219 0.142 0.70 2.58 0.224 0.156 351 E.1.5 Calculating Plume Contrasts Impacts are calculated for the range of scenarios described below. To eliminate repetition, only the impacts on the view to the west (A1 = 270°) are presented here. Azimuth = Al = 270° a = 36° BM = 1300 eN = 90° aA = 31°* x = 60 kmt Stable plume conditions: 0.429 = 0.40 un T = 0.078 a = 0.55 NO2 0.004 X = 0.70 0.083 A = 0.40 un part = 0.078 a = 0.55 0.074 a = 0.70 * As p (a,e) values are given in appendix B only for even degree values of e, subsequent calculations assume a eA = 360 . t For each transport/azimuth scenario, x is taken to be the transport distance to the intersection of the plume centerline and the line of sight. 352 (Sulfate is not considered for the stable plume scenarios.) Values of pplume are taken from appendix 6: a Scenario 9 M N A 1300 900 360 0.40 un 0.159 0.203 2.22 0.55 0.142 0.219 2.45 0.70 0.156 0.224 2.58 % ackground = 0.95 The value of bext is determined by summing the values for b (units of km-1) shown below: X bR bsa-submicron bsa-coarse baa bext 0.40 0.037 0.013 0.004 0.001 0.055 0.55 0.010 0.008 0.004 0.001 0.023 0.70 0.004 0.005 0.004 0.001 0.014 Also, for calculating sky/terrain contrast reduction: ro = 55 km* Co = -0.9 t fobj = 1 From terrain elevation plot (figure E-3a). t i.e., the entire plume is assumed to be between the mountains of view 1 and the Visitors' Center. 353 Intermediate calculations are made for the following parameters: m _ Tpart ')plume TN02 + Tpart 0.162 a = 0.40 un 0.501 a = 0.55 0.946 a = 0.70 TNO2 + 'part c = `plume sin a (0.871 = S 0.265 0.734 a = 0.40 um x = 0.55 a = 0.70 rp = 0.199 x - 20 km sin a- Given the above, plume contrast is calculated according to: (p '))plume plume - _ exp(- Tplume) exp(-bext rp) . '))background Scenario 1A--Morning, a = 0.55 un: C _ (0.142)(0.5014- _ 1 1 - exp(-0.24S) exp (-0.0230)-(20) plume Cpl ume = - 0.127 354 Scenario 1B--Morning, a = 0.40: Cplume .- (0.159)(0.162) _ 1 1 - exp(-0.87) exp [(-0.055) - (20)� Cplume = -0.187 Scenario 1C--Morninq, a = 0.70: C _ r(0.156) (0.946) exp(-0.12,4)� {exD I�-0.014) (20)� plume Lfi�j' L l L Cplume = -0.059 E.1.6 Calculating Reduction in Sky/Terrain Contrast Caused By Plume Using the above data, we calculate eCr according to: AC = -Co exp(-bext ro) 1 -C 1 + r exp(-fobj plume)) . plume Scenario 1A--Morning, a = 0.55 im: . AC r =-(-0.9) exp [ (0.0230) - 55] 1 - - - --i1 exp [-1 - (0,26S)] AC = 0.031 Scenario 1B--Morning, a = 0.40 um: ACr =-(-0.9) exp[-(0.055)(55)] 1 - _ 1 + exp[-1 - (0.87)] AC = 0..021 r Scenario 1C--Morning X = 0.70 um: ACr =-(-0.9) exp[-(0.014)(55)] 1 - _ 1 + exp[-1 - (0.13 )] A ti AC = 0.030 r 355 For the stable transport situation, we may summarize our results for the morning view toward the west as shown: X Co 1 ume Acr 0.40 -0.187 0.021 0.55 -0.127 0.031 0.70 -0.059 0.030 These values indicate that though significant reduction in visual range is not expected (1nCrl < 0.1), a perceptible yellow -brown plume is likely to be visible in some situations (ICplumel > 0.1). E.1.7 General Haze Effects The same values for many parameters are used for assessing general haze effects. Aside from the differences in calculated values for optical thickness, the principal differences are Tplume = Taerosol = 0.0229 rp=50km fobs = ro/100 km = 0.55 �=1 For the westerly morning view at 0.55 un, we have = I(O.560)(b—.95T (0.142)(1) _ 1 1_exp(-0.0229)exp(-0.0230 - 50)Cplume 1 [ ] [ I = -0.005 356 Also, eCr = -(0.9) [exp(-0.023 - 55)] 11 - - , 1 + exp (-0.55 - 0.0229), = 0.002 E.1.8 Comparison of Results with Reference Tables The example described above corresponds reasonably closely to the hypothetical 500 Mwe power plant of appendix D. as shown in table E- 5 . TABLE E-5. COMPARISON OF EXAMPLE POWER PLANT EMISSIONS AND APPENDIX D POWER PLANT EMISSIONS Emissions Hypothetical 500 Mwe Example Power Plant Power Plant Qpart (MT/day) 1.6 2.2 QNOx (MT/day) 14.5 10.4 QS02 (MT/day) 29.0 32.8 The scenario descriptions, though somewhat different, are still close enough to provide useful results, as shown in table E-6. TABLE E-6. COMPARISON OF SELECTED SCENARIO DESCRIPTORS RH 1031background Simulation date/time Scattering angle Wind speed Background visual range Appendix D Example 40% 0.04 ppm 23 September/1000 90- 2.5 m/s 100 and 200 km 40% 0.05 ppm 21 December/0900 130- 2 m/s 170 km 357 At a downwind distance of 50 km, with a 200 km visual range, appendix D shows a blue -red ratio of 0.892, which indicates that the plume would probably be perceptible. This agrees quite favorably with the hand cal- culated value of 0,064. The modeled plume contrast of -0.031 at 0.55 urn is significantly lower than the hand calculated value of -0.13. This is due to the differences in input parameters between the hand calculation and the model. Also, the hand calculation procedure is conservative for this backward scatter case (e = 130°) since multiple scattering is ignored. The AE(L*a*b*) value of 4.5 (dropping to 3.37 by the 75 km down- wind distance) indicates a marginally perceptible plume. Visual range reduction is insignificant at 0.6 percent, a result which agrees with the hand calculation showing &Cr of 0.031 at 0.55 trn. The downwind effect profiles shown in the plots in appendix D indicate that, at downwind distances of 50 to 75 km, model results are relatively insensitive to downwind distance for all parameters except blue -red ratio, which peaks fairly sharply at approximately 25 km. The difference in the blue -red ratio plots between the 2.5 and 5 m/s scenarios indicates a substantial sensitivity to wind speed, a factor that con- tributes to the difference in the magnitude of results between the hand calculations and appendix D results. The assumption of 100% NO-NO2 con- version also contributes to this difference. In general, the results above indicate a potential concern only for the visibility effects of NOx emissions from the proposed facility. Par- ticulate and S02 emissions appear unlikely to cause perceptible impairment of visibility in either general haze or coherent plume scenarios. Additional (level-3) analysis is probably warranted for this facility, if design parameters (specifically NOx emissions rates) remain as originally stated. In particular, the significance of potential effects can be better evaluated given a more thorough analysis of the fre- quency of occurrence of meteorological regimes associated with perceptible impacts in and around the class I area, and a more precise determination of anticipated NOx chemistry in the plume. 358 E.2 EXAMPLE 2--CEMENT PLANT AND RELATED OPERATIONS A cement plant has been proposed, along with related quarrying, materials handling, and transportation facilities, for a location 20 km away from a class I area. Terrain in the -vicinity is relatively flat, and no external vistas from the class I area (a national park) are considered integral to park visitors' experiences. Visibility within the park boundaries is of concern, however. The proposed project would cause both elevated emissions from numerous process points and ground -level emissions of fugitive dust. Estimated emissions rates and particle -size distributions are shown in table E-7. For the level-1 screening, a downwind distance (x) of 20 km is used, along with the corresponding oz, for F stability of 46 m. As before, the calculations are carried out in sequence. E.2.1 Level-1 Analysis 2.0 x 108 P - v x z p = 1.67 x 105 Tpart = 10-6 P • Qpart x=20km vz=60m Qpart = 4.93 MT/day* ( = 4.54 + .395) * For the initial screening, it is conservatively assumed that the emissions are released from a common point. 359 TABLE E-7. ESTIMATED PROJECT EMISSIONS Emissions Emissions Rates Particulate Matter Process Sources 0.395 MT/day (effective stack height = 50 m) DG=1un cg = 2 p = 2 gm/cm 3 Fugitive Emissions 4.54 MT/day DG=10un cg = 2 R = 2 gm/cm3 Sulfur Oxides 7.26 MT/day (effective stack height = 50 m) Nitrogen Oxides 2.72 MT/day (effective stack height = 50 m) 360 Tpart = 0.822 TN02=1.7x10-7•p •QNOx ONOx = 2.72 MT/day TN02 = 0.0771 Taerosol ' 1.06 x 10-5 • rv0 - (Qpart + 1.31 • QSO2) rvO = 60 km* Qpart = 4.93 QS02 = 7.26 Taerosol = 0.00918 TN 02 C = 1 - exp - Tpart a TNO exp -0.78 x/rv0 1 Tpart + TN02 2 C1 =-0.0392 C2 = 1 - C 1+ I exp - part TNO exp -1.56 x/rv0 1 2 C2 = 0.343 C3 = 0.368 [1 - exp (- Taerosol)] C3 = 0.00336 * Taken from figure 12, text page 56, for the proposed location. 361 The values for C1, C2, and C3 are characteristic of major particulate sources with relatively low NOX and SOX emissions. Both C1 and C3 (NO2 discoloration and general haze indicators) are sufficiently low to indi- cate relatively little possibility of perceptible impact. However, C2 indicates the potential for a perceptible particulate plume. It should be noted, however, that the level-1 calculations were based on the following two specific conservative assumptions: > All particulate emissions are assumed to have been released from a comfnon point, resulting in the creation of a single, coherent plume. Most of these emissions are, in fact, fugitive emissions released near ground level. > Particle scattering efficiency is assumed to be sig- nificantly higher than would be expected for the OG = 10 vm fugitives. Because level-1 procedures cannot address these issues, a level-2 assess- ment is indicated. It is worth noting, however, that plume discoloration resulting from NO2 is unlikely, as are problems associated with general haze. Therefore, the level-2 analysis need only concentrate on those parameters related to estimation of particulate plume effects. E.2.2 Level-2 Analysis An analysis similar to that shown for example I (section E.1.2.2) indicates that a 0 stability 1 m/s wind speed scenario corresponds most closely to the 1-percentile worst -case diffusion. Because there are no terrain features that might affect the flow of pollutants toward the park, the transport distance for analysis remains at 20 km. Therefore, as Qz for stability class 0 at 20 km is 200 m, the reasonable worst -case Ulu value is 200 m2/s. 362 The park itself is also relatively flat, with sizable (20 km) internal open vistas. Because all internal vistas are potentially impacted at all times of the day, scattering angles between 0° and 180° are of potential concern. A range of angles covering backscatter, forward scatter, and side lighting of the plume are selected for analysis. As a means of simplifying the level-2 screening calculations, it is assumed (as in level-1) that for calculation of visibility impacts, all emissions are released from a common point. General haze has been eliminated in the level-1 screening; therefore, SOX emissions need not be considered, because the level-2 procedures do not incorporate short-term sulfate formation. NO2 formation, on the other hand, must be considered, because of the effect of NO2 on plume perceptibility. Particulates constitute the major potential problem for the proposed project, as indicated by the C2 value of 0.343. There are two major groups of particulate emissions, each of which warrants separate treat- ment. Process emissions constitute a relatively small proportion of the total mass emissions rate (< 10%); however, their size distribution (DG = 19 a = 2) has a much greater scattering efficiency than the larger, fugi- tive emissions (DG = 10 ag = 2).* To distinguish between these emissions types, the calculations below have various parameters that are subscripted "pros" and "fug", to indicate the process (fine) emissions and fugitive (coarse) emissions, respectively. The calculations of particulate impacts begin with determination of plume optical depth, based on the equation * This example is based, in part, on cement plants, which will typically have bag -house controlled process emissions -,(and therefore no coarse particle emissions) and fugitive emissions, which are generally large particles. Fugitive emissions result from materials handling, quarrying, haul roads, and so on. 353 Qscat-part - 1160 Qpart bscat/v ' p 1+ Both Qpart and bscat/v take different values for the different types of emissions. Therefore Qscat-part is determined separately for each type of emissions. Qpart-pros = 0.395 MT/day DGproc - 1 un °g proc - 2 pproc - 2 gm/cm 3 (bscat/v) proc ' 0.05 Qscat-part proc = 11.5 m2/s Qpartf u = 4.54 MT/day DGfug = 10 un agf ug - 2 3 Pfug = 2 gm/cm bscat/vf ug ' 0.004 Qscat-part fug = 10.5 m2/s Note that despite the relative difference in mass emission rates, the pro- cess emissions dominate the scattering coefficient flux at the assumed emissions point. For simplicity, it will be assumed that all emitted par- ticles remain suspended in the plume. This conservative assumption need not be made; it is possible, though somewhat tedious, to calculate the settling of large particles from the plumO On the other hand, if the * From figure 24. t Stokes settling velocities can be calculated, according to the equa- tion cs = 3 x 10-3 pd2, where cs 3s the settling velocity (in cm/s), p is the particle density (in gm/cm ), and d is the particle diameter (in wn). This equation is an approximation of the Stokes velocity equation, and it is approximately accurate for particles larger than about 2 vm. 364 less conservative meteorological scenarios of this level-2 analysis and the lower scattering efficiency of large particles result in calculated effects below perceptible levels, then no purpose is served by projecting settling effects. Should potential effects be projected under assumed conditions, then the decision can be made either to rework the level-2 analysis with consideration for settling or to go to a level-3 analysis. Consideration of table 4 also indicates a possible simplification of calculations. Because of the size of particles emitted, there is little wavelength dependence of scattering coefficients. Therefore, we may restrict consideration of scattering effects to a single wavelength, a = 0.55 un. Proceeding with the analysis, we have: 6.17 QNO [NOxI = x oz u x QNOx = 2.72 MT/day azu = 200 m2/s x=20km [NOx] = 0.0042 ppm Even at extremely low background 1031, it should be assumed that total conversion of NO to NO2 will occur at concentrations below 0.02 ppm. Therefore, [N021 = 0.0042 ppm 365 Continuing, we have: TN02 = 0.398 [N021 (babs/PPm) babs/pPm10.55 = 0.31 TN02 = 0.010 As stated previously, sulfate impacts need not be considered. Therefore, we need consider only Tpart- Qscat-part Tpart 2 (2,r)Zu Qscat- art proc + Qscat-part fug (2n)1/2 a2u Tpart = 0.0439 bext (a=0.55 tim) = 3.912 rv0 bextl0.55 = 0.065 Qscat-part proc = 11.5 m2 /s Qscat-part fug = 10.5 m2/s azu = 200 m2/s rv0 = 60 bscat = 0.95 bext bscat = 0.062 km-1 9 bsp = bscat - bR -5-1 bRIz=400m = 1.06 x 10m 0.011 km-1 bsp = 0.051 b spsubmicron = 0.67 bsp = 0.034 km-1 bsp coarse = 0.33 bsp = 0.017 km-1 Phase functions are determined for the background air mass and the plume at scattering angles of 220, 44 % 90 % and 136 % as shown in table E-8. Because of the assumed bimodal particle -size distribution, average values for the plume phase function are calculated. These plume average values are weighted using the values of Qscat-part proc and Qscat-part fug according to the equation P( .X, O) av plume = Qscat-part proc p( a, e)oroc + Qscat-part fug P( '�, e)fug Qscat-part proc + Qscat-part fug Finally, we determine Cplume and eCr using the following values: a = 90 ° Tpart = 0.044 TN02 = 0.010 . 367 TABLE E-8. BACKGROUND AND PLUME ATMOSPHERE PHASE FUNCTIONS AND SCATTERING COEFFICIENTS (a = 0.55 un) Phase Function p(a,o) for Indicated 0 Background Atmosphere Scattering Component bscat (km-1) 220 440' 900 1360 Rayleigh Scattering 0.011 1.39 1.12 0.75 1.125 Due to air molecules at site elevation Mie Scattering Submicron Aerosol O.a34 5.36 2.01 0.318 0.188 DG = 0.3 un ag = 2.0 Coarse Aerosol 0.017 3.20 1.08 0.160 0.0740 DG = 6 m ag = 2.0 Total (average) 0.062 4.06 1.60 0.351 0.323 Phase Function p(a,o) Plume Scattering for Indicated 0 Component Qscat-part 220 440 90" 1360 Process Emissions 11.5 5.92 1.57 0.218 0.175 DG = 1 un ag = 2 Fugitive Emissions 10.5 2.70 1.28 0.138 0.0344 DG = 10 un ag = 2 Plume average 22 4.38 1.43 0.180 0.108 Kw TNO + part Tplume sin a = 0.054 r- _O.199x_4km p s i—. n —a - bext = 0.065 ro = 5 km Co = -0.9 fobj=l _ Tpart = 0.814 $fume TNO 2 + Tpart °bkg = 0.95 Cplume and oCr are determined according to: _ (p`�)plume _ Cplume pb1 1 - exp - plume exp-bextrp AC = -Co exp -bextro 1 1 + exp -fobj Tplume plume On the basis of these equations, and the p(a, e) from table E-8, we com- pute the impact projections shown in table E-9. 369 TABLE E-9. PROJECTED PLUME CONTRAST AND CONTRAST REDUCTION FOR EXAMPLE 2 ( X = 0.55 un) Cplume Acr Scattering Angle (0) 220 440 900 1360 -0.003 0.032 1 �1� 0.028 -0.023 0.020 -0.029 0.016 These results show that visibility impacts would probably be imper- ceptible for the situation described. Therefore, further analysis is not warranted. Note that the combined effects of the less conservative meteorology (D,1 versus F,2), the consideration of particle -size distribu- tion, and the more precise formulation of visibility impact parameters in level-2 have provided a substantially different description of expected impacts from that which might be extracted from the level-1 results. 370 REFERENCES Altshuller, A. P. (1979). "Model Predictions of the Rates of Homogeneous Oxidation of Sulfur Dioxide to Sulfate in the Troposphere," Atmos. Enyiron., Vol. 13, pp. 1653-1661. Briggs, G. A. (1972), "Discussion on Chimney Plumes in Neutral and Stable Surroundings," Atmos. Enyiron., Vol. 6, pp. 507-610. Briggs, G. A. (1969), "Plume Rise," U.S. Atomic Energy Commission Critical Review Series, TID-25075, National Technical Information Service, Springfield, Virginia. Briggs, G. A. (1971), "Some Recent Analyses of Plume Rise Observations," Proc. of the Second International Clean Air Congress, H. M. Englund and W. T. Berry, eds., (Academic Press, New York, New York), pp. 1029-1032. Dixon, J. K. (1940), "Absorption Coefficient of Nitrogen Dioxide in the Its1ble Spectrum," J. Chem. Phys.,,Vol. 8, pp. 157-160. Duffie, J. A., and W. A. Beckman (1974). Solar Energy Thermal Processes, (John Wiley and Sons, New York, New York). Holzworth, G. C. (1972). "Mixing Heights, Wind Speeds, and Potential for Urban Air Pollution throughout the Contiguous United States," AP-101, Office of Air Programs, Environmental Protection Agency, Research Triangle Park, North Carolina. Land, E. H.,(1977), "The Retinex Theory of Color Vision," Sci. Am., Vol. 237, pp. 108-128. Latimer, D. A., et al. (1978). "The Development of Mathematical Models for the Prediction of Anthropogenic Visibility Impairment," EPA-450/3-78- 110a, b, and c, available from NTIS as PS 293118 SET. Latimer, D. A., T. C. Daniel, and H. Hogo (1980). "Relationships between Air Quality and Human Perception of Scenic Areas," Publication no. 4323, American Petroleum Institute, Washington, D.C. 371 Latimer, D. A., et al. (1980a), "Modeling Visibility," invited paper presented at American Meteorological Society/Air Pollution Control Association, Second Joint Conference on Applications of Air Pollution Meteorology, 24-27 March, New Orleans, Louisiana. Latimer, D. A., et al. (1980b), "An Assessment of Visibility Impairment in Capitol Reef National Park Caused by Emissions from the Hunter Power Plant," EF80-43, Systems Applications, Incorporated, San Rafael, California. Liu, M. K., and D. R. Durran (1977), "The Development of a Regional Air Pollution Model and Its Application to the Northern Great Plains," EPA-908/1-77-001, U.S. Environmental Protection Agency, Region VII, Denver, Colorado. Malm, W. C., et al. (1979). "Visibility in the Southwest," unpublished manuscript. Middleton, W.E.K. (1952). Vision Through the Atmosphere. (University of Toronto Press, Toronto, Canada Randerson, D. (1972), "Temporal Changes in Horizontal Diffusion Parameters of a Single Nuclear Debris Cloud," J. Appl. Meteor., Vol. 11, pp. 670-673. Schulz, E. J., R. B. Engdahl, and T. Particles from a Pulverized Coal 9, pp. 111-119. T. Frankenberg (1975), "Submicron Fired Boiler," Atmos. Environ., Vol. Singh, H. B., F. L. Ludwig, and W. B. Johnson (1978), "Tropospheric Ozone: Concentrations and Variabilities in Clean Remote Areas," Atmos. Environ., Vol. 12, pp. 2185-2196. Trijonis, J., and D. Shapland. (1979), "Existing Visibility Levels in the U.S.," EPA-450/5-79-010, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina. Turner, D. B. (1969), "Workbook of Atmospheric Dispersion Estimates," U.S. Department of Health, Education, and Welfare, Public Health Service Publication No. 999-AP-26. 372 Whitby, K. T., and G. M. Sverdrup (1978), "California Aerosols: Their Physical and Chemical Characteristics," ACHEX Hutchinson Memorial Volume, Particle Technology Laboratory Publication Number 347, University of Minnesota, Minneapolis, Minnesota. Williams, M. D., E. Treiman, and M. Wecksung (1980). "Plume Blight Visibility Modeling with a Simulated Photograph Technique," J. Air Pollut. Contr. Assoc., Vol. 30, pp. 131-134. 373 TECHNICAL REPORT DATA (Please read Instructions on the reverse before completing) 1. REPORT NO. 2. 3. RECIPIENT'S ACCESSION NO. EPA-450/4-80-031 4. TITLE AND SUBTITLE WORKBOOK FOR ESTIMATING VISIBILITY IMPAIRMENT 5. REPORT DATE November 1980 6. PERFORMING ORGANIZATION CODE 7. AUTHOR(S) 8. PERFORMING ORGANIZATION REPORT NO. Douglas A. Latimer and Robert G. Ireson 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT NO. Systems Applications, Inc. 950 Northgate Drive 11. CONTRACT/GRANT NO. San Rafael, California 94903 68-02-0337 12. SPONSORING AGENCY NAME AND ADDRESS Office of Air Quality Planning and Standards 13. TYPE OF REPORT AND PERIOD COVERED U. S. Environmental Protection Agency 14.SPONSORING AGENCY CODE Research Tri'angle Park, North Carolina 27711 15. SUPPLEMENTARY NOTES 16. ABSTRACT This workbook is designed to provide three screening procedures to assist in determining the potential impacts of an emissions source on a Federal Class I area's vt'sitItty. It does not address the cumulative impacts of multiple sources on regional haze. A level-1 analysis involves a series of conservative screening tests to elimi~nate sources with little potential for visibility impairment during hypo- thettcal worst -case meteorological conditions. If impairment is indicated, a more resource intensive level-2 analysis is warranted. If both analyses indicate impairment a level-3 analysis using a plume visibility model should be used. Two example-, applicatiens are provided; for a coal-fired power plant and a cement plant. 17. KEY WORDS AND DOCUMENT ANALYSIS 1 a. DESCRIPTORS b.IDENTIFIERS/OPEN ENDED TERMS C. COSATI field/Group Atr Pollution New Source Review 13 B Meteorology Point Sources 4 A Atmospheric Diffusion 4 B Air Qualt1ty Modeling Visibility Sulfates Aerosols 18. DISTRIBUTION STATEMENT RELEASE TO THE PUBLIC 19. SECURITY CLASS (ThisReporf) None 21. NO. OF PAGES 390 20. SECURITY CLASS (This page) 22. PRICE 1:-A Form ZZZO-1 (Rev. 4-77) PREVIOUS EDITION IS OBSOLETE