The Subtropical Cloud Transition: From the Turbulence Scale to Global Climate

Abstract:

Subtropical boundary layer cloud regimes such as stratocumulus, cumulus and the transition from stratocumulus to cumulus, play a key role in cloud-climate interactions. Recent studies have highlighted the lack of complete understanding of this transition and the fact that climate models do not simulate in a realistic manner the physics of the transition. In this presentation, recent results on the global characterization of the subtropical cloud transition from satellite data are used to illustrate its essential properties and the key questions remaining for a complete understanding of the transition. Large-Eddy Simulations (LES) and observations of the cloud transition are used to develop parameterizations, simple models of the transition and a better understanding of the dynamics that leads to the ultimate demise of stratocumulus and its potential impact on climate change.