Integrative Investigation of Contrasting Aerosol–Cloud Interactions

Scattered pieces of observational evidence have been reported that show contrasting relationships between key cloud microphysical properties (e.g., droplet concentration, relative dispersion, or effective radius) and aerosol properties (e.g., aerosol concentration or aerosol optical depth); however, much remains elusive. This study is an effort at addressing this perplexing topic, with three objectives. First, we will analyze and compare aircraft measurements conducted under different environments including heavily polluted clouds in China, less polluted clouds at ARM SGP, and clean marine clouds. Second, parcel model experiments will be designed according to the empirical analysis to explore the physical mechanisms underlying the contrasting evidence for aerosol-cloud interactions. Third, efforts will be made to develop parameterizations for representing these contrasting aerosol-cloud interactions in large scale models. A major thrust of this study is to develop a comprehensive investigation and physical understanding of the loosely reported contrasting aspects of aerosol-cloud interactions.