Regional Climate Model Results for Climate Impacts Applications

Eric Salathé

Science & Technology Program, UW BothellClimate Impacts Group, UW Seattle

Alan Hamlet (UW), Neil Banas (UW), Brian Lamb (WSU)

Regional climate change scenarios

• “Downscale” global scenarios to add local details

• There is a hierarchy of methods depending on the details needed

• More sophisticated methods can expand the class of impacts problems we can consider

• Should downscaling change the large-scale trends from the global model?

Climate Impacts Group 2009, WA Assessment, Ch. 1http://cses.washington.edu/cig/res/ia/waccia.shtml

Figure shows change compared with 1970 -1999 average

Composite IPCC AR 4 Simulations for the Pacific Northwest

A1B Medium HighB1 Low Jan Jul

Delta Method:Simplest Climate Change Scenarios

Application of Delta Method:

Change in Long-Term Mean April 1 Snowpack

Snohomish River Near Monroe, WA

Regional Climate Model12-km WRF

0 50 100 150 200 250 300 3500

10,000

20,000

30,000

40,000

50,000

Chehalis RiverAnnual one-day peak flow

30 years current (blue) and future (red)

1980s 2050s

Peak Flow date

Pea

k F

low

(cf

s)

1 2 20 50 1000

40,000

80,000

Chehalis River

Historical (1980s)_WRF Climate Change (2050s)_WRF

Return Years

Flo

ws

(cfs

)

Multi-scale and Ensemble Modeling of Global Change and Air Quality

Summer TemperatureDifferences from 1990s to 2050s

Change in T (°C)

PCM-MM5 A2 ECHAM5-WRF3 A1BECHAM5-WRF2 A1B

CCSM3-WRF2 A1B CCSM3-WRF2 A2

Summer Mixed-layer DepthDifferences from 1990s to 2050s

Change in PBL (m)

A1B_Base – Current Decade Average Daily 8-hr Maximum O3

June through August

Several ppb increase in O3 throughout most of the countrySlight decrease in O3 along west and east coastal zones

Linking Climate, Ocean, BiologyNOAA ECOHAB

Steph Moore, NOAA NWFSCEric Salathé, UW BothellCheryl Greengrove, UW TacomaNeil Banas, UW APLNate Mantua, UW Fish

Alexandrium Catenella

Delta Method:Future HAB projections

The “Window of Opportunity” for Harmful Algal Blooms (HAB-WOO)

Projected to become more frequent and last longer

Moore, Mantua and Salathe, 2011

Projected changes in summertime along-shore winds

Stronger northerly winds -> more upwelling

Conclusions

• Different approaches are needed for different applications

• What information can we get from climate models?

• What is left out that we need to know• How can we add that information?