But soil moisture, for example, increases in the global model, but not in the regional model. The researchers, who also included Giang Nong, graduate student in meteorology and John Haynes, undergraduate in meteorology, analyzed the global and regional models for twice today's carbon dioxide levels. Overall, the global models produced consistently high precipitation. However, the regional model does a better job at producing rainfall amounts similar to observation. The two-times carbon dioxide regional climate simulation for the Northeastern United States produced warmer temperatures, leading to more rain and less snowfall during winter.
Less snow means less snowpack for spring melting.
The snowpack is important because snow melts slowly, rather than running off immediately. The regional models rely on the global models for input. Problems arise when interpolating to increase the number of data points 30 times. One way the researchers tested the models was to try to simulate present-day extreme events, like El Nino or the drought of 1988. Precipitation looks like a simple variable, but it is really complex.