1. Eric Salathé Climate Impacts Group (JISAO/SMA) University of Washington Constructing regional climate change scenarios

4. What do Global Models do?  Simulate the global circulation patterns  Can be derived from observations for verification  Precipitation and Temperature is what would occur with global circulation and smooth Earth  Does not correspond to observations

7. Local Scaling

8. Effect of Wind Patterns Wind from SouthWind from Southwest Weak Rainshadow Strong Rainshadow

9. Monthly Flow in Yakima River

11. Downscaled ECHAM4 IPCC A2 -121.7 47.5 (Snoqualmie Pass)

12. “Delta” method -- scale the historic data by the climate-change signal: Statistical downscaling,-- remove bias in climate-change Precipitation using the historic data: The choice is where the time-series characteristics are taken from: History or Model?

13. Percent of years with precipitation In bottom 20% of Historic Range What is the Climate Signal?

14. Regional Climate Models Probably not best primary tool for impact studies Several research issues 1. “Second Order” effects Cold air outbreaks marine layer moves inland. 2. Orographic precipitation response to warming 3. ENSO response

15. Comparison of RCM and Statistical Downscaling Of Reanalysis GCM Arbitrary point on Cascade Crest

17. Regional Climate Models Probably not best primary tool for impact studies Several research issues 1. “Second Order” effects Cold air outbreaks marine layer moves inland. 2. Orographic precipitation response to warming 3. ENSO response

18. Summary 1/8-degree P, Tmin, Tmax for IPCC scenarios What information should we take from models? What information should we take from historic record? What can we (should we) learn from regional climate models?