members g. danabasoglu(co-chair) national center for atmospheric research, usa
DESCRIPTION
CLIVAR Imperative IV: Improved atmosphere and ocean component models of Earth System Models. Members G. Danabasoglu(co-chair) National Center for Atmospheric Research, USA H. Drange (co-chair) University of Bergen, Norway M. MarslandCSIRO, Australia - PowerPoint PPT PresentationTRANSCRIPT
MembersG. Danabasoglu (co-chair) National Center for Atmospheric Research, USAH. Drange (co-chair) University of Bergen, NorwayM. Marsland CSIRO, AustraliaS. Griffies Geophysical Fluid Dynamics Lab., NOAA, USAG. Madec LODYC, Institute Pierre Simon Laplace, FranceR. Greatbatch Institut für Meereskunde, Kiel, GermanyH. Tsujino Met. Res. Inst., Japan Meteorological Agency, JapanE. Curchitser Rutgers University, USA
EmeritusC. Böning Institut für Meereskunde, Kiel, GermanyA. M. Treguier Laboratoire de Physique de Océans, IFREMER, FranceR. Gerdes Alfred Wegener Inst., GermanyE. Chassignet Florida State University, USA
OrganizerA. Pirani ICPO
Boulder, 23-26 Sep 2010
Sea ice/ice shelves Ocean biogeochem Ocean numerics
D. Holland (USA) K. Fennell (Canada) G. Nurser (UK)
CLIVAR Imperative IV: Improved atmosphere and ocean component models of Earth System Models
Two parallel approaches
Model development Model simulationsand analysis
Level, layer and hybrid models
Resolution & parameterizations
Numerics (accuracy, efficiency, consistency, etc.)
Test-bed for development of the ocean component in ESMs
Biogeochemistry (particularly CO2 and ocean acidificaiton) and tracers
Ice shelves (coming)
Downscaling/shelf modelling
Curchitser et. al.
Two parallel approaches
Model development Model simulationsand analysis
Level, layer and hybrid models
Resolution & parameterizations
Numerics (accuracy, efficiency, consistency, etc.)
Test-bed for development of the ocean component in ESMs
Biogeochemistry (particularly CO2 and ocean acidificaiton) and tracers
Ice shelves (coming)
Downscaling/shelf modelling
Atmospheric forcing
Spin-up procedure
Model evaluation against observations
Model comparison (but no MIP)
Analysis of interannual to decadal variability
Analysis of mechanisms
Sensitivity experiments
Main WGOMD activities(i) Workshops facilitating collaboration, communication, education - 2004 Princeton State of the Art in Ocean Climate Modelling - 2005 Hobart State of the art in Southern Ocean Modelling - 2007 Bergen Numerical Methods for Ocean Models - 2009 Exeter Ocean Mesoscale Eddies: Repr, Parameterizations, Obs - 2010 Boulder Decadal Variability, Predict, and Prediction: Role of the Ocean
(ii) Coordinated Ocean-Ice Reference Experiments (CORE I-III) - Benchmark simulations, with detailed protocols, for global ocean-ice models
(iii) Repository for Evaluating Ocean Simulations (WGOMD REOS) - Web-based tool for evaluating ocean simulations
(iv) White papers - Hurrell et al. (2009), Decadal Climate Prediction: Opportunities and Challenges, OceanObs´09 - Griffies et al. (2009), Problems and Prospects in Large-Scale Ocean Circulation Models, OceanObs´09 - Griffies et al. (2008), Sampling Physical Ocean Fields in WCRP CMIP5 Simulations
(v) Review and more specific peer-reviewed OGCM articles
CORE (Co-ordinated Ocean-Ice Reference Experiments)
Provide a workable and agreeable experimental design for global ocean-ice models to be run for long-term climate studies; should be useful for experts and newcomers
Establish a framework where the experimental design is flexible and subject to refinement as the community gains experience and provides feedback
• CORE-I Multi-century spin-up with repeating “Normal Year Forcing” (Large and Yeager, 2004; Griffies et al., 2009, Ocean Modelling)
• CORE-II: 1948-present; interannually varying forcing (Large and Yeager, 2004 & 2009)
• CORE-III Fresh water melt perturbation idealizing the melt of water around Greenland (Gerdes et al., 2006, Ocean Modelling)
• CORE IV Heat perturbation / partial coupling (being discussed)
Ongoing WGOMD synthesis work
Generate an archive of model outputAnalysis of multi-model results
Working group+ meeting, Jan 2012 in Venice
Helge DrangeGeophysical InstituteUniversity of Bergen
Max
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Example of spin-up of OGCMs
Helge DrangeGeophysical InstituteUniversity of Bergen
Strong SSS relaxationWeak SSS relaxation + restoring
Max
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Example of spin-up of OGCMs
1988-2007 time mean diagnostics (best forcing, ok observational support)
• Poleward heat transport: global, Atlantic, Indo-Pacific • Poleward fresh water transport: global, Atlantic, Indo-Pacific • SST, SSS, SSH, MLD (wintertime and summertime mean) • Overturning (global, Atlantic-Arctic, Indo-Pac) depth and sigma-2 space• Zonal mean temp and salinity relative to observations • Total heat flux, P-E+R entering ocean• Map of restoring/correction salt flux converted to an implied water flux • Hemispheric average annual cycle of sea ice
Ongoing WGOMD synthesis work
Variability defined with respect to 1988-2007 mean
• Standard deviations of annual mean SST, SSS, SSH, overturning streamfunction (depth and density by basin)• MLD, summer, winter, mean, std• Tropical thermocline std (across all basins)• Tropical cells• T14C depth standard deviation• Outcropping, mean position, std• Formation, propagation, decay of T/S-anomalies• Upper ocean heat content anomaly• Thermosteric and halosteric sea level
Ongoing WGOMD synthesis work
Trends and changes
• Comparison with observed trends• Look for shifts in Atlantic and Pacific to define • The time mean minus the time mean • SST, SSS, SSH• Zonal mean temp and salinity
Case studies for
• North Atlantic • Indian Ocean• Pacific Ocean• Southern ocean • Arctic Ocean
Ongoing WGOMD synthesis work
Illustration of sensitivities
• Changes to precip at high latitudes• Changes in zonal wind trend in Southern Ocean• Role of buoyancy and mechanical forcing for abrupt shifts• More general discussion of the role that CORE-II plays in helping feedback on the development of atmospheric states to force the ocean-ice models
Ongoing WGOMD synthesis work
Intention to duplicate part of the analysis to the CMIP5 ensemble
Helge DrangeGeophysical InstituteUniversity of Bergen
Sensitivity experiments
Helge DrangeGeophysical InstituteUniversity of Bergen
Post 1995 forcing
Control integration (1995; “real model world”)
Lohmann et al.
EasyInit project CLIVAR meeting on decadal predictions, at KNMI, November 2009:
modeling community had suggested and requested that ocean reanalysis are being provided in an “EasyInit” project that can
support the coupled modeling community to ease the initialization of decadal prediction runs using ocean reanalyses
Aim: The modeling community can get all reanalysis in a “one-stop” fashion and with a uniform format Host: The KlimaCampus of the University of Hamburg (D. Stammer)
* http://www.clisap.de/Easy-INIT.easyinit.0.html* presently 8 (?) reanalyses are (more or less) available for comparison and analysis