Sensitivity of Marine Cloud Macro- and Micro-physical Response to Idealized Wildfire Aerosol Forcing off the Western US Coast

We investigate the impact of 10x increase in global black and organic carbon aerosol emissions from wildfires on subtropical marine clouds off the western coasts in atmosphere-ocean coupled/uncoupled, low-resolution/high-resolution configurations of Department of Energy’s Energy Exascale Earth System Model (E3SMv2). The high-resolution model in E3SMv2 refers to the North American Regionally Refined Model configuration where the model’s horizontal resolution over and around North America is about 25km, and 100 km otherwise. To limit the impact of the slower ocean response to the forcing, we conduct a 10-member short 1-yr coupled simulation ensemble, instead of the 10-yr long simulations conducted for the other experiments. We also compare the response to 10x increase in emissions globally vs. only regionally over North America.