Downscaling Climate Models

For this project, we will expand on the methods of Frelich (2009), in which 16 global circulation models were averaged together for the moderate A2 emissions scenario.  Those results were used to create downscaled projections for future temperature and precipitation on 12 x 12 km grid squares in Minnesota, considering climate variation caused by landscape lake effects, physiography, latitude and longitude (Galatowitsch et al. 2009). Future climate scenarios for 2030-2039 and 2060-2069 were draped over the state of Minnesota, and future climate analogs were delineated for each of eight ecoregions of the state. Climate analogs for 2069 under high emissions scenarios are similar to the currently prevailing climates 400-500 km to the south-southwest of each ecoregion.

We will use similar methods and expand the analysis to MN, WI and MI, for a longer time frame (through 2100), and for more scenarios to bracket the range of possible future climates. For the proposed work we will do the RCP 4.5 and RCP 8.5 scenarios, bracketing the range of future possibilities and overall mean scenario. For each of the model outputs we will calculate the temperature and moisture regime throughout the year at the resolution of the 12 x 12 km downscaled grid. We will also calculate the projected growing degree days at each cell because this will be used in tree, mammal, and bird species responses. These changes will be calculated for each year from 2014 to 2030, and then at 10-year intervals until 2100.