气候变化领域集成服务门户(CCPortal): Numerically Relevant Timescales in the MG2 Microphysics Model

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DOI	10.1029/2019MS001972
	Numerically Relevant Timescales in the MG2 Microphysics Model
	Santos S.P.; Caldwell P.M.; Bretherton C.S.
发表日期	2020
ISSN	19422466
卷号	12 期号:4
英文摘要	Climate models rely on parameterizations of a variety of processes in the atmospheric physics, but a common concern is that the temporal resolution is too coarse to consistently resolve the behavior that individual parameterizations are designed to capture. This study examines timescales numerically derived from the Morrison-Gettelman (MG2) microphysics as implemented within the Energy Exascale Earth System Model, version 1 (E3SMv1). Numerically relevant timescales in MG2 are derived by computing the eigenspectrum of its Jacobian. These timescales are found to often be smaller than the default 5 min time step used for MG2. The fast timescales are then heuristically connected to individual microphysics processes. By substepping a few particular rain processes within MG2, the time discretization error for those processes was considerably reduced with minimal additional expense to the overall microphysics. While this improvement has a substantial effect on the target processes and on the vertical distribution of stratiform-derived rain within E3SMv1, the overall model climate is found to not be sensitive to MG2 time step. We hypothesize that this is because the surface climate does not depend strongly on certain process rates, especially MG2's rain evaporation rate. ©2020. The Authors.
英文关键词	cloud microphysics; global circulation model; physics parameterizations; time resolution
语种	英语
scopus关键词	Geophysics; Rain; Atmospheric physics; Earth system model; Evaporation rate; Overall-model; Surface climate; Temporal resolution; Time discretization; Vertical distributions; Climate models; climate modeling; cloud microphysics; design; evaporation; numerical method; parameterization; rainfall; temporal analysis; vertical distribution
来源期刊	Journal of Advances in Modeling Earth Systems
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156731
作者单位	Department of Applied Mathematics, University of Washington, Seattle, WA, United States; Lawrence Livermore National Laboratory, Livermore, CA, United States; Department of Atmospheric Sciences, University of Washington, Seattle, WA, United States
推荐引用方式 GB/T 7714	Santos S.P.,Caldwell P.M.,Bretherton C.S.. Numerically Relevant Timescales in the MG2 Microphysics Model[J],2020,12(4).
APA	Santos S.P.,Caldwell P.M.,&Bretherton C.S..(2020).Numerically Relevant Timescales in the MG2 Microphysics Model.Journal of Advances in Modeling Earth Systems,12(4).
MLA	Santos S.P.,et al."Numerically Relevant Timescales in the MG2 Microphysics Model".Journal of Advances in Modeling Earth Systems 12.4(2020).