(729c) Warm Cloud Collision-Coalescence and the Influence of Aerosol Properties

Aerosol particles influence cloud formation and precipitation, but the nature and quantification of these interactions remain highly uncertain. The magnitude of metrics used to quantify the effect of aerosol on clouds and precipitation has been shown to depend on factors such as meteorological regime, cloud type, region, and data collection/analysis techniques. While satellite-based investigations of aerosol-cloud-precipitation studies often relate responses of cloud microphysical and macrophysical properties to aerosol perturbations, a topic that has received less attention is that of the physicochemical nature of aerosol particles. Collocated aerosol, cloud, and precipitation data from the A-Train are used over a period of 32 months starting in June 2006 to examine this issue. We show that aerosol cloud interactions are sensitive to the physicochemical properties of aerosol. Our results provide new insight into the role of aerosol properties in altering the collision-coalescence time scale for warm clouds. In addition to previous work, we show that the choice of using aerosol optical depth or aerosol index will lead to varying magnitudes of aerosol-cloud interactions and that current estimates of aerosol-cloud interactive terms and parameterizations of processes such as autoconversion overlook the importance of aerosol type.