Statistical Downscaling for the Pacific Northwest

Results for IPCC Fourth Assessment global climate model simulations

The Climate Impacts Group has analyzed the climate response for the Pacific Northwest simulated by several climate models. These simulations were prepared by climate modeling centers worldwide for the Fourth IPCC Assessement. For consistency with prior work, we include the current versions of models used previously: Hadcm3, Echam5, CCSM3, and PCM1 (CCSM3 is the successor to both the NCAR CSM and DOE PCM). To these we added 5 additional models to better represent the range of models participating in AR4. These are: CNRM_CM3, CSIRO_MK3 Miroc_3.2, IPSL_CM4, CGCM_3.1, and GISS_ER. Summary statistics for these models are provided in the link at the right.

From these, we have selected

• ECHAM5 SRES A2 simulation as the middle of the road senario
• IPSL_CM4 A2 as the highest warming scenario
• GISS_ER B1 as the lowest warming scenario

These models have been downscaled to daily 1/8-degree data for the Pacific Northwest. Data coverage is indicated by the map at right, which shows the downscaled distribution of precipitation for the 2040s.

Daily and monthly-mean data may be downloaded here.

Publications

• E. P. Salathé Jr, P W Mote, M W Wiley, 2007: Review of scenario selection and downscaling methods for the assessment of climate change impacts on hydrology in the United States pacific northwest. Int. J. of Climatology, In press. Published on-line, 25 Jun 2007; DOI: 10.1002/joc.1540. [Draft PDF]
• E. P. Salathé Jr., 2006: Influences of a shift in North Pacific storm tracks on western North American precipitation under global warming, Geophys. Res. Lett., 33, L19820, doi:10.1029/2006GL026882. [Abstract] [Draft PDF]
• E. P. Salathé Jr. 2004: Methods for selecting and downscaling simulations of future global climate with application to hydrologic modeling. International Journal of Climatology, 25, 419-436. [Draft PDF]
• E. P. Salathé Jr. 2003: The effect of various precipitation downscaling methods on the simulation of streamflow in a rainshadow river basin, Int. J. of Climatology, 23, 887-901. [HTML | PDF]
• Widmann, M., C. S. Bretherton, and E. P. Salathe, 2002: Statistical precipitation downscaling over the northwestern United States using numerically simulated precipitation as a predictor. J. Climate, 16, 799-816. [HTML | PDF | PS]