Understanding and Parameterization of Compensating Aerosol-Cloud Interaction Factors for Improving Climate Models

 

Authors

Yangang Liu — Brookhaven National Laboratory
Chunsong Lu — Nanjing University of Information Science and Technology
Jingyi Chen — Stony Brook University

Category

Warm Low Clouds and Interactions with Aerosol

Description

Despite progress in understanding of aerosol-cloud interactions and their representation in climate models, climate models still suffer from a large uncertainty in estimated aerosol indirect effects and a large discrepancy compared to observations. It has been increasingly recognized that these outstanding problems are likely related to the factors that compensate or buffer the aerosol indirect effect as conventionally represented in climate models. This study will review and report our research on four potentially important but poorly understood such factors related to warm clouds: 1) regime dependence of cloud properties with increasing aerosol concentration, 2) dispersion effect associated with the changes in the spectral shape of the cloud droplet size distribution, 3) effect of entrainment-mixing processes, and 4) scale-dependence. We will also explore their mutual relationships in the context of improving representation of aerosol-cloud interactions in climate models, and seek a systems approach that considers cloud-environment interactions via environment, turbulent mixing in clouds, and aerosols. New formulations on regime quantification and relationships between aerosol, vertical velocity and entrainment rate will be presented. Future direction will be discussed.