Regional Climate: Current Research

Developing a Database of Regional Climate Change Scenarios



As part of the Intergovernmental Panel on Climate Change (IPCC) assessment, global climate models have been run for historical conditions and for future scenarios of anthropogenic forcing, providing simulated climate from 1900-2100. These models, however, do not simulate the detailed features of the regional weather and climate necessary for addressing regional impact studies. Using an efficient statistical downscaling method, the Climate Impacts Group (CIG) is developing an extensive database of regional climate scenarios based on the IPCC global simulations.

Research Questions


The CIG has applied statistical downscaling methods to produce high-resolution maps of temperature and precipitation from various climate change simulations in the IPCC collection of models and scenarios, and is in the process of creating an extensive database of downscaled scenarios. These results are directly applicable to studies where high spatial resolution, multiple scenarios, and a long time span are desired. Currently, the CIG is applying these results to several water resource management studies (e.g. Seattle Public Utilities). In the example in Figure 1, the ECHAM4 model is downscaled at 1/8-degree resolution over the Pacific Northwest using the method in Salathé (2003). Daily data from 1990 to 2060, three models (ECHAM4, HADCM3, NCAR-PCM), and two IPCC emission scenarios (A2 and B2) have been produced with this method. The method in Wood et al. (2002) has been applied to an ensemble of runs with the NCAR-PCM model.

click image to enlarge

Map of the Pacific Northwest region of the United States, highlighting the Columbia River Basin

Figure 1 Downscaled temperature (“Tmax ” monthly mean maximum daily temperature, degrees Celsius) and precipitation (monthly mean, mm/day) for January 2020 from the ECHAM4 global climate model run with the A2 SRES scenario.

Selected References

For more publications on climate impacts on Pacific Northwest (PNW) climate, please see CIG Publications.

Salathé, E. P. 2003. Comparison of various precipitation downscaling methods for the simulation of streamflow in a rainshadow river basin. International Journal of Climatology 23:887-901.

Widmann, M., C. S. Bretherton, and E. P. Salathé. 2003. Statistical precipitation downscaling over the northwestern United States using numerically simulated precipitation as a predictor. Journal of Climate 16:799-816.

Wood, A. W., E. P. Maurer, A. Kumar, and D. P. Lettenmaier. 2002. Long-range experimental hydrologic forecasting for the eastern United States. Journal of Geophysical Research-Atmospheres 107:4429.