Observational constraints for cloud water response to aerosols

It has been a challenge to estimate aerosol indirect effects associated with cloud water response to aerosols. Here we compare several different metrics, including precipitation susceptibility, for their ability to constrain cloud water response to aerosols in climate models. Multi-sensor aerosol and cloud products from A-Train satellites are further used to quantify uncertainties in observational estimates of precipitation susceptibility. The scale-dependence of the estimate of the precipitation susceptibility is quantified using a regional climate model WRF-Chem. Constraining cloud water responses to aerosols based on long-term observations are further explored.