Seminar

Abstract

Satellite imagery shows that cloud fields over large areas of the ocean often organize into either highly reflective closed cellular convection or much less reflective open cellular convection. Whether cloud fields prefer one state or the other can have a profound effect on the amount of sunlight reflected back to space, with important implications for Earth’s climate. Precipitation is thought to be a necessary but insufficient condition for the transformation of closed to open cellular convection; observations often show high rain rates existing within the closed cells.

In this talk we will test the hypothesis that the spatial distribution of precipitation is a key element of the transition from closed-to-open cellular convection. A series of idealized 3-dimensional model simulations are conducted to evaluate the dependency of the transformation on the areal coverage of rain, and to explore the role of interactions between multiple rainy areas in the formation of the open cells. We will show that a combination of the spatial distribution and intensity of the rain are key factors determining whether cloud fields prefer the closed or open cellular state.