estuarine hypoxia component of testbed 2
DESCRIPTION
Estuarine Hypoxia Component of Testbed 2. Marjorie Friedrichs, VIMS, lead Carl Friedrichs, VIMS, co-lead Wen Long and Raleigh Hood, UMCES Malcolm Scully, ODU. FY12 Testbed 2 Kick-off Telecon. Objectives. - PowerPoint PPT PresentationTRANSCRIPT
Estuarine Hypoxia Component of Testbed 2
Marjorie Friedrichs, VIMS, leadCarl Friedrichs, VIMS, co-lead
Wen Long and Raleigh Hood, UMCESMalcolm Scully, ODU
FY12 Testbed 2 Kick-off Telecon
Compare relative skill of various hydrodynamic and dissolved oxygen models in reproducing observations on seasonal time scales in Chesapeake Bay, by examining:
bottom/surface temperaturebottom/surface salinitybottom/surface dissolved oxygenmaximum stratificationdepth of maximum stratificationhypoxic volume
Provide information to managers such that results of these analyses could be transitioned to operational/scenario models
Objectives
Five Hydrodynamic Models Configured for the Bay
CH3DCerco & Wang
USACE
ChesROMSLong & Hood
UMCES
UMCES-ROMSLi & Li
UMCES
CBOFS (ROMS)Lanerolle & Xu
NOAA
EFDCShenVIMS
• ICM: CBP model; complex biology• BGC: NPZD-type biogeochemical model• 1eqn: Simple one equation respiration
(includes SOD)• 1term-DD: depth-dependent respiration
(not a function of x, y, temperature, nutrients…)
• 1term: Constant net respiration
Five biological models
Data from 40 CBP stations
mostly 2004some 2005 results
bottom T, bottom S, stratification = max dS/dz,
depth of max dS/dz
bottom DO, hypoxic volume
= ~40 CBP stations used inthis model-data comparison
Stratification (max dS/dz; 2004)
Stratification is a challenge; CH3D, EFDC reproduce seasonal/spatial variability best
unbiasedRMSD
[psu/m]
bias [psu/m]
Stratification is insensitive to grid resolution and changes in atmospheric forcing
CH3D, EFDC
ROMS
Sensitivity ExperimentsMaximumStratification
Stratification (max dS/dz; 2004)
Adjusting the minimum TKE parameter reduces the bias in ChesROMS
unbiasedRMSD
[psu/m]
bias [psu/m]
ROMS withnew TKEparameter
Hypoxic Volume
unbiasedRMSD[km3]
bias [km3]
Several simple DO models reproduce seasonal variability of hypoxic volume about as well as ICM
Hypoxic Volume
unbiasedRMSD[km3]
bias [km3]
5-model average does better than any single model
1. Compared 5 different hydrodynamic modelswith 5 different DO models (examined 12 different combinations of hydrodynamics+DO for 2004, subset of these for 2005)
Density stratification at pycnocline is a challengeSimplest DO models reproduce seasonal variability
as well as most complex modelsMulti-model average for hypoxic volume does better
than any single model
Models do much better in our wet year (2005) than our
dry year (2004)2. Began to examine sensitivity experiments with individual models
Strong sensitivities to wind, min TKE, advection scheme
Weak sensitivities to river discharge, coastal BC, grid resolution
Overall Progress from Testbed 1
3. Transitioning information to federal agencies
• Simple DO model incorporated into the research version of NOAA CSDL’s Chesapeake Bay Operational
Forecast System• Participated in Eco-Forecasting workshop at
NOAA/ NCEP to further hammer out transition steps for
moving to fully operational version of the DO model• Provided advice to the CBP on future estuarine
and hypoxia modeling strategies, in support of federally mandated environmental restoration, via a STAC workshop report
Overall Progress from Testbed 1(cont.)
We are on track to provide all deliverables as promised by Dec. 31, 2011
Update on Testbed 1 Deliverables
1. Improve modeled density stratificationExamine choice of turbulence closure scheme and advection scheme
2. Idealized sensitivity experiments with all modelsConcentrating on wind, may also include river
discharge
3. Additional skill metricAveraged Discrete Frechet Distance
4. Presentations/publicationsFive publications are in preparationMultiple presentations to managers and
scientific community
Plans for Testbed 2 Year 1
1. Unstructured GridsSELFEFVCOM
2. Potential for < 10 day operational forecastsNeed to examine skill of models in reproducing
high frequency data sets
3. Interannual/Interdecadal skillWe have simulations from 1991-2005 from
multiple models, but we do not yet have the resources to make these comparisons
“Wish List” for Testbed 2