. Anthropogenic air Pollution Delays Marine Stratocumulus Cloud Break-up

Abstract
The effect of aerosols on clouds albedo is the largest when the background aerosol levels are low. This leads to the perception that adding aerosols to the present day already high aerosol levels would make a small change in the cloud radiative forcing. Here we exploit a novel approach of realistic Lagrangian large eddy simulations, coupled with satellite observations, to show the contrary. We demonstrate that transitions between fully cloudy and broken Marine stratocumulus clouds, which exert the largest aerosol cloud-mediated radiative forcing, are far from being saturated. This is manifested by a nearly linear relationship between the aerosol concentrations in which the clouds form and the time it takes the clouds to break-up. Our findings imply that Sc remain longer and cover larger areas over oceans when being more polluted, thereby inducing a potentially large cloud radiative forcing.