Impact of subgrid-scale radiation variability on the marine stratocumulus to trade cumulus transition

Poster PDF

Description

Interactions between turbulence and radiation on scales smaller than climate model grid columns are important for accurately simulating marine low clouds. To better understand the impacts of these interactions, large eddy simulations of the stratocumulus-to-trade cumulus (Sc-to-Cu) transition have been performed for the GEWEX Atmospheric System Studies (GASS) composite Lagrangian transition case and the Atlantic Trade Wind Experiment (ATEX) case. It is shown that the lack of subgrid-scale turbulence-radiation interaction, as is the case in current generation climate models, accelerates the Sc-to-Cu transition. The findings suggest including subgrid-scale interactions between the radiation and turbulence parameterizations could remedy some common deficiencies in simulations of the Sc-to-Cu transition. Implications for parameterizing the turbulence-radiation interactions will be discussed.