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Evaluation of IPCC Global Climate Models for North Pacific Marine Ecosystem Applications . Nicholas A. Bond University of Washington/JISAO. Outline. Excerpts from recent work (e.g., Capotondi et al. 2012 and Furtado et al. 2011)
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Evaluation of IPCC Global Climate Models for North Pacific Marine Ecosystem Applications Nicholas A. Bond University of Washington/JISAO
Outline • Excerpts from recent work (e.g., Capotondi et al. 2012 and Furtado et al. 2011) • Results from some CMIP3 runs along with a few CMIP5 runs under the RCP8.5 scenario • Musings
Capotondi et al. (2012) 2050-2099 vs. 1950-1999
Capotondi et al. (2012) psu mm per day
Capotondi et al. (2012) (Surface to 200 m) Potential density (kg/m3)
Changes in February Mixed Layer Depth from Present to 2040s (standard deviations)
Changes in Mean August Mixed Layer Depth from Present to 2040s (standard deviations)
Skill of Global Climate Model (DHFP1) for PDO Prediction Lienert (Ph.D., 2011)
*Z *Z *Transport *Z * *Both Transport* Temperature X-Section
Parameters Evaluated • Bering Sea - Flow through Unimak Pass (Nutrient supply); Spring Winds (Larval flatfish transports); Summer SST & Wind Mixing (Sustained productivity); etc. • Gulf of Alaska - Along-coast winds (Larval fish distribution and abundance); Precipitation (Upper ocean baroclinity and eddy generation) • NE Pacific - Coastal upwelling (Productivity); Zonal winds (LTL communities); Pycnocline depth; Upper-ocean transports
Seward Line * PAPA Alaska Peninsula Vancouver Is. Newport
Feb SODA ECHAM5 PCM1 Aug Average Temperatures 1990-2000 MirocM MirocH MRI
Feb SODA CCCMAT47_1 CCCMAT47_2 Aug Average Temperatures 1990-2000 CCCMAT47_3 CCCMAT47_4 CCCMAT47_5
Mean Zonal Currents in Vertical Plane along 170 W From HadGEM2CC and GFDLESM2G models
Quasi-quantitative Assessment of Global Climate Model Capabilities
Considerations • Recent research (e.g., Furtado et al. 2011) indicates that current GCMs, in general, do not replicate observed ENSO-North Pacific linkages that well • Past performance no guarantee of skill in future projections (e.g., Reifen & Toumi2009) • Unclear whether weighting or even omitting ensemble members provides any meaningful benefits (e.g. Pierce et al. 2009) • Inter-model dominates intra-model variability for projections longer than 1-2 decades • Lack of community consensus on best practices in the use of GCMs for regional applications
Final Remarks • From present to mid-21st century, climate change liable to be dominated by thermodynamic effects as opposed to dynamic effects (e.g., winds). • Open questions: (1) Are the ocean components of global climate models sufficient for climate/ecosystem studies? (2) Are the new CMIP5 models significantly better than the CMIP3 models? (3) What is the best way to use existing climate model simulations for regional applications? • The output from global climate models (perhaps subject to statistical downscaling) can complement that from vertically-integrated numerical models with full dynamics.