Role of Dynamical and Physical Processes in Simulated Extremes Due to Climate Change

Both 20th and 21st simulations from the Community Earth System Model (CESM) are used to explore the relative contributions of changes to dynamical and physical processes in changes in extremes in precipitation statistics and geographic location. Precipitation changes due to greenhouse gases and aerosol forcing arise from shifts in both the large-scale dynamical transport of water vapor and changes in cloud physics such as convective versus large-scale processes. Using a suite of simulations from the CESM that involve differing parameterized physics and horizontal resolutions we explore the relative factors leading to changes to the extreme precipitation for specific geographic regions. We also compare the simulations to observations from 20th century simulations to assess which processes are more realistically captured in the versions of the CESM.