Open AccessMultiple‐Instance Superparameterization: 2. The Effects of Stochastic Convection on the Simulated Climate
Author(s) -
Jones Todd R.,
Randall David A.,
Branson Mark D.
Publication year - 2019
Publication title -
journal of advances in modeling earth systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.03
H-Index - 58
ISSN - 1942-2466
DOI - 10.1029/2019ms001611
Subject(s) - madden–julian oscillation , precipitation , oscillation (cell signaling) , climate model , convection , atmosphere (unit) , meteorology , environmental science , scale (ratio) , climatology , computer science , statistical physics , climate change , physics , geology , oceanography , genetics , quantum mechanics , biology
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.