气候变化领域集成服务门户(CCPortal): Toward Parametrization of Precipitating Shallow Cumulus Cloud Organization via Moisture Variance

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DOI	10.1029/2021JD034939
	Toward Parametrization of Precipitating Shallow Cumulus Cloud Organization via Moisture Variance
	Thomas M.L.; Bašták Ďurán I.; Schmidli J.
发表日期	2021
ISSN	2169-897X
卷号	126 期号:15
英文摘要	The influence of the initial vertical moisture profile on precipitating shallow cumulus cloud organization in terms of the column-averaged moisture variance is investigated using large-eddy simulations. Five idealized simulations based on the Rain in Cumulus over the Ocean field experiment with different initial moisture profiles are investigated. All cases simulate precipitating shallow cumulus convection in a marine sub-tropical region under large-scale subsidence. The results show that the moisture variance is mainly generated through the interaction of the moisture flux and the moisture gradient in the gradient production term at the top of the boundary layer. The development is characterized by three regimes: initial, transition, and quasi-steady regime. During the initial regime, the moisture gradient is built up by moisture accumulation until precipitating convection starts. Within the transition regime, precipitation enables mesoscale cloud organization with enhanced convective activity and moisture fluxes. The moisture variance increases from the moist to the dry initial moisture profiles. In a following quasi-steady regime, the moisture variance is approximately preserved. Thereby, the initial moisture gradient between the average sub-cloud layer and the free atmosphere is found to be an important factor for the generation of the quasi-steady column-averaged moisture variance. The result suggests that a resolved-scale variable like the moisture gradient can be used to estimate the quasi-steady state conditions resulting from cloud organization. This finding may serve as a starting point for the parametrization of the subgrid scale cloud organization caused by precipitating shallow convection. © 2021. The Authors.
英文关键词	atmospheric boundary layer; cloud organization; large-eddy simulation; shallow cumulus convection
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/237090
作者单位	Institute for Atmospheric and Environmental Sciences, Goethe-University, Frankfurt am Main, Germany; Institute for Atmospheric Physics, Johannes Gutenberg University, Mainz, Germany
推荐引用方式 GB/T 7714	Thomas M.L.,Bašták Ďurán I.,Schmidli J.. Toward Parametrization of Precipitating Shallow Cumulus Cloud Organization via Moisture Variance[J],2021,126(15).
APA	Thomas M.L.,Bašták Ďurán I.,&Schmidli J..(2021).Toward Parametrization of Precipitating Shallow Cumulus Cloud Organization via Moisture Variance.Journal of Geophysical Research: Atmospheres,126(15).
MLA	Thomas M.L.,et al."Toward Parametrization of Precipitating Shallow Cumulus Cloud Organization via Moisture Variance".Journal of Geophysical Research: Atmospheres 126.15(2021).