Multiple‐Instance Superparameterization: 2. The Effects of Stochastic Convection on the Simulated Climate

Journal of Advances in Modeling Earth Systems

Mark D. Branson¹  David A. Randall¹  Todd R. Jones² 

[1] Department of Atmospheric Science Colorado State University Fort Collins CO USA;Department of Meteorology University of Reading Reading UK;

关键词: climate;    parameterization;    convection;    stochastic;    deterministic;    MJO;   

DOI  :  10.1029/2019MS001611

来源: DOAJ

【 摘 要 】

Abstract The cloud‐permitting model (CPM) of the superparameterized Community Atmosphere Model (SP‐CAM) is a stochastic parameterization. As reported in a companion paper, we have created a variant of SP‐CAM, called MP‐CAM, that uses the averaged feedback of 10 independent two‐dimensional CPMs in each global model column, in place of the single CPM of SP‐CAM. This ensemble‐averaged feedback is interpreted as an approximation to the feedback from a deterministic parameterization. We present evidence that the multiple‐instance superparameterization of MP‐CAM is indeed more deterministic than SP‐CAM. The climates of the SP and MP configurations are compared, giving particular attention to extreme precipitation events and convectively coupled large‐scale tropical weather systems, such as the Madden‐Julian Oscillation. A number of small but significant changes in the mean state climate are uncovered, and the deterministic parameterization slightly degrades the Madden‐Julian Oscillation simulation.

【 授权许可】

Unknown