Assessing Aerosol Wet Removal Efficiency in Conventional and Multiscale Modeling Framework Configurations of the Community Earth System Model

Abstract Aerosol particles play a crucial role in the global climate by absorbing and scattering radiation and influencing cloud properties. This study explores the role of resolved convection on precipitation and subsequent removal by wet deposition of aerosol in the Community Earth System Model (CESM2.1.0) by comparing two configurations with distinct representations of precipitation characteristics. We contrast the conventionally parameterized configuration (CAM5‐ZM) with the multiscale modeling framework (CAM5‐MMF), which uses embedded 4 km cloud‐resolving models to explicitly simulate convection. We compare the results against observations from Integrated Multi‐satellite Retrievals for Global Precipitation Measurement, MODIS, MERRA2 Reanalysis, and simulations from GEOS‐Chem and Aerocom. The CAM5‐MMF configuration better captures the frequency and intensity of rainfall by reducing the overestimation of light precipitation frequency in CAM5‐ZM. Improved precipitation frequency is associated with aerosol lifetimes and removal rates that better match observations, leading to higher black carbon and primary organic matter burdens, with implications for future climate forcing and air quality changes.