County-scale Climate Projections over Minnesota for the 21st Century
Abstract
Minnesota is the U.S. state with the strongest winter warming in the contiguous United States. We performed regional climate projections over Minnesota at 10 km horizontal resolution using the Weather Research and Forecasting (WRF) model forced by an ensemble of eight general circulation models (GCMs) from the Climate Model Intercomparison Project version 5 (CMIP5) that have previously been found to be in relatively good agreement with observations over Minnesota. Our projections suggest ongoing warming in all seasons, especially in winter, as well as shallower snow cover and fewer days with snow cover. On the other hand, we expect significant increases in spring and early summer heavy precipitation events. Our comparisons between different time slices and two different emission scenarios indicate a climate for the state of Minnesota at the end of the 21st century that is significantly different from what has been observed by the end of the 20th century. Winters and summers are expected to be up to 6oC and 4oC warmer, respectively, over northern and central Minnesota. Fig. 1 shows average winter (December-February) 2-meter air temperature in oC from the multi-model ensemble mean for (a) historical simulations and (b-d) anomalies of each RCP scenario compared to the historical period. Shading in (b-d) indicates statistically significant changes over U.S. land points at the 95% confidence interval. Please note that there is a different color bar for (a) than for (b-d). Spring precipitation may increase by more than 1 mm d-1 over northern Minnesota. Especially over the central part of the state, winter snow height is suggested to decrease by more than 0.5 meters and the number of days per year with snow height of more than 0.0254 meters (one inch) is expected to decrease by up to 60. A manuscript describing initial findings from this work is currently under review for the journal Earth and Space Science at https://doi.org/10.1002/essoar.10507340.2
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFMGC32C..04L