HomeMy WebLinkAboutDesign Cook Inlet Shelikof Straits Circulation Modeling System NOAA/AEA RichardPatchen 08-24-2011-AO f f i c e o f C o a s t S u r v e y / C o a s t S u r v e y D e v e l o p m e n t L a b
Design and Implementation of a NOAA/NOS Cook Inlet
and
Shelikof Straits Circulation Modeling System
Richard Patchen and Lyon Lanerolle
Presented at a NOAA/AEA Stakeholders Meeting,
August 24, 2011, Anchorage Alaska
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Programmatic Objectives
Develop Improved Navigational Products for the Region
Support Known Requirements for the Region
o Marine Operations –Oil and Gas Platform and Port Facilities (Anchorage)
Resource Management –Alaska Departments of Fish and Game and Natural
Resources
o Coastal Sciences –Climate Change/ocean acidification/coastal ecology, Kasitsna
Lab, Kachemak Bay NERR, AOOS, and Universities
o Oil Response –NOAA’s ORR, Coast Guard, Cook Inlet Regional Citizens Advisory
Council (CIRCAC), and local communities
o Recreation –Charter sportfish industry, marine ecotourism
o Renewable Energy –AGREEMENT BETWEEN THE NATIONAL OCEANIC AND
ATMOSPHERIC ADMINISTRATION NATIONAL OCEAN SERVICE AND THE ALASKA
ENERGY AUTHORITY FOR A BASELINE ASSESSMENT OF TIDAL KINETIC ENERGY
IN COOK INLET, AK
o Web enabled tide and tidal current charts and tables
o Operational Forecast System (OFS)
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o Validated and calibrated ocean and hydrodynamic models can
effectively address some critical uncertainties. Models are
needed, both at the scale of a few turbines to address potential
near-field effects and at regional scales to address potential
far-field effects.
o Project and device developers should work with
oceanographers and other researchers to share and discuss
monitoring data collection, modeling methodologies, and study
results
Proceeding from a Scientific Workshop Held on
Environmental Effects of Tidal Energy
Development, March 22-25, 2010
O f f i c e o f C o a s t S u r v e y / C o a s t S u r v e y D e v e l o p m e n t L a b
Areas of significant hydrokinetic energy potential in Alaska (yellow triangles) and
areas with pending or issued FERC permits (red triangles)
From Proceeding of Environmental Effects of Tidal Energy Development,
March 22-25, 2010
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Model Simulation Strategy and Sequence
•Configure a regional model -uses Rutgers University’s
Regional Ocean Modeling System (ROMS)
o Conduct a series of tidal simulations, without emerging and
submerging shoals and constant density
•Establish a Digital Elevation Model (DEM)
o Based on most recent Bathymetries Shorelines, and Topographies
•Enhance Regional model with local highly resolved nests,
using the DEM
o Conduct a series of hindcasts
o Validate with historical and newly collect observations
•Complete Baseline Assessment of Tidal Kinetic Energy in
Cook Inlet
•Establish NOAA Operational Forecast System for Region
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Model Domain and Bathymetry
Shelikof
Straits
Kachemak
Bay
Upper Cook
Inlet
Nests
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Model Grid Spatial Resolution
1000 m
200 m
2000 m
100 m
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Development of the Shelikof Straits –Cook
Inlet Digital Elevation Model (DEM)
•Need a DEM to account for flooding/drying
especially in upper CI
•DEM is built by combining :
Bathymetric sounding data
Shoreline data
Land topography data
•DEM needs to be seamless without “jumps”
between above data sets
•Need to account for different native datums of
the datasets
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DEM Development: Bathymetry
•Bathymetric soundings were from NOS surveys in the Shelikof Straits
–Cook Inlet region
•Soundings have been quality controlled
•Soundings cover 1907–2004, 2008–2009 periods
•Data in Bathymetric Attributed Grid (BAG) file format need to be
converted to ASCII before use
•All datasets are on a MLLW vertical datum
•Soundings interpolated to ROMS model grid in a supersession
sequence (2009 1907)
•Spatial interpolation via a 1/r2 algorithm with three expanding “radii” :
±½(∆x, ∆y), ±(∆x, ∆y), ±3/2(∆x, ∆y) around model “wet” grid nodes
•The model grid “wet point” interpolation domain was determined by the
MLLW shoreline
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DEM Development: Shoreline
MHW shoreline relative to MLLW datum
MLLW shoreline
•Continue to use a MLLW vertical datum
•On MLLW shoreline assume h = 0 (m)
•Apply datum correction to MHW shore-
line so that it has h > 0 relative to a MLLW
datum (next slide)
•Using (i) previously interpolated bathymetry
(at wet points) and (ii) MLLW shoreline with
h = 0 and (iii) MHW shoreline with h > 0,
spatially bi-linearly interpolate to define
model grid point depths between the two
shorelines on a MLLW datum
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DEM Development : Vertical Datum
Transformations
Bi-linear interpolation
Observed MSL,
MHW, MHHW,
MLLW heights and
their differences
from NOS/CO-OPS
data sheets
Pseudo-data points
to facilitate spatial
interpolation (to
generate datum
difference fields)
O f f i c e o f C o a s t S u r v e y / C o a s t S u r v e y D e v e l o p m e n t L a b
DEM Development: Land Topography
•Land topography from two sources –USGS digitized elevation data
and NOAA/NESDIS/NGDC 1/3” DEM for Kachemak Bay
•USGS data 4 spatial resolutions –1/9”, 1/3”, 1” and 2”
•Datum for USGS unclear but zero-elevation contour matches
NOAA/NESDIS/NGDC MHW shoreline well
•Assume both data sources are on a MHW vertical datum
•Interpolate USGS data from highest to lowest spatial resolution (1/9”
2”)
•Use same numerical interpolation algorithm as for bathymetry
•Clip topography at 15m elevation
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The Shelikof Straits –Cook Inlet DEM
•Interpolated bathymetry and
shoreline on MLLW brought to
MSL
•Interpolated topography on MHW
also brought to MSL
•DEM fully on MSL vertical datum
•Land topo. clipped at 15m height
•Needed to re-define land/sea
masks on model grid
Interpolated Topography
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Present Status
•Completed construction of a DEM for the region
•Completed initial configuration of the regional model and
conducted a series of tidal simulations, without emerging
and submerging shoals and constant density.
o The M2 simulation provided:
a suitable calibration mechanism
evidence that water elevation amplitude and phases were very accurate
evidence that currents comparisons degrade in upper CI
evidence that the most effective bottom drag formulation was the Log
formulation
o A non flooding/drying simulation with 8 ADCIRC tidal constituents showed
that :
water elevation phases were very accurate
water elevation amplitudes have ~50 cm (~12.5%) error in upper CI
model predicted currents have very accurate phases
the currents profiles deform in the upper CI region
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LOG LOG LOG
Preliminary Examples of Renewable Energy
Characteristics for Cook Inlet and Shelikof Straits
Near Surface Mid-Depth Near Bottom
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LOG LOG
Preliminary Examples of Renewable Energy
Characteristics for Cook Inlet and Shelikof Straits
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Acknowledgments
•Doug Graham (NOAA/NOS/NGS) –MLLW shoreline
•Dean Gesch and Gayla Evans (USGS, South Dakota) –USGS 1/9”
topography dataset and guidance on using USGS topography and vertical
datum issues
•Barry Eakins (NOAA/NESDIS/NGDC) -Vertical datums for topography
•Dan Roman and Xiaopen Li (NOAA/NOS/NGS) -Datum transformation
choices
•Kris Holderied (NOAA Kasitsna Bay Lab)-Kachemak Bay integrated ocean
mapping, tidal energy collaboration concept, NOAA regional collaboration
team
•Darcy Dugan (AOOS) -Cook Inlet modeling workshop/ongoing workgroup,
stakeholder outreach
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Backup Slides
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M2 Water Elevation Validation
WE Comparison Stations WE Ampl. and Phase Comp.
•Model calibrated via M2 amplitude and phase along domain axis
•Very sensitive to choice of bottom drag formulation –Log form. best
O f f i c e o f C o a s t S u r v e y / C o a s t S u r v e y D e v e l o p m e n t L a b
M2 Current Validation
Lower Cook Inlet Upper Cook Inlet
•In lower CI, both M2 amplitude and phase from model and obs. compare well
•In upper CI, phases compare well but model ampl. is damped relative to obs.
O f f i c e o f C o a s t S u r v e y / C o a s t S u r v e y D e v e l o p m e n t L a b
Tidal Water Elevation Validation
Ampl. Error (cm) Component Phase Error (min.) Component
•Amplitude errors increase when moving up CI and are ~50 cm
•Model predicted phases are highly accurate and are under 12 min.
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Tidal Currents Validation
Lower Cook Inlet Upper Cook Inlet
•Currents in lower CI match tidal predictions well
•In upper CI, the phases are accurate but model current profiles are distorted