Reconciling Compensating Errors Between Precipitation Constraints and the Energy Budget in a Climate Model
Takuro Michibata, Kentaroh Suzuki
Abstract
Abstract Precipitation microphysics and the effective radiative forcing due to aerosol‐cloud interactions ( ERF aci ) contribute to some of the largest uncertainties in general circulation models (GCMs) and are closely interrelated. This study shows that a sophisticated, two‐moment prognostic precipitation scheme can simultaneously represent both warm rain characteristics consistent with satellite observations and a realistic ERF aci magnitude, thus reconciling compensating errors between precipitation microphysics and ERF aci that are common to many GCMs. The enhancement of accretion from prognostic precipitation and accretion‐driven buffering mechanisms in scavenging processes are found to be responsible for mitigating the compensating errors. However, single‐moment prognostic precipitation without the explicit prediction of raindrop size cannot capture observed warm rain characteristics. Results underscore the importance of using a two‐moment representation of both clouds and precipitation to realistically simulate precipitation‐driven buffering of the cloud response to aerosol perturbations.