Two Missing Key Ingredients in Unlocking the Aerosol and Warm Cloud Interactions (Invited Presentation)

Aerosol-cloud-precipitation system is a very complex and chaotic system, many of whose behaviors remain mysterious. Much of the mysteries stem from a lack of knowledge of clouds themselves. This talk concerns two cloud properties that are important modulators of aerosol-cloud interactions but have been largely missed in the aerosol indirect effect community, namely, (1) convective updrafts at cloud bases and (2) the degree of cloud-surface decoupling. The former governs the activation of cloud-forming aerosols at cloud bases and the latter determines how many surface originated aerosols can reach the cloud bases. Moreover, changes in these two variables are often associated with specific configurations of meteorological states at multiple scales, which adds additional forcing (and additional level of complexity) to the aerosol-cloud-precipitation system. In this talk, two scientific questions are asked: (1) what are the physical mechanisms that govern the behaviors of these two cloud properties? and (2) how to apply the knowledge to disentangle the aerosol effects on clouds from meteorology? To tackle these problems, various tools are utilized in a synthesized way: field experimental observations, satellite imageries and retrievals, simple analytical model, and idealized process-level simulations. Limitations and future challenges will be discussed.