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标题：The role of precipitation and spatial organization in the response of trade‐wind clouds to warming
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作者：Raphaela Vogel ; Louise Nuijens ; Bjorn Stevens 等
期刊名称：Journal of Advances in Modeling Earth Systems
电子版ISSN：1942-2466
出版年度：2016
卷号：8
期号：2
页码：843-862
DOI：10.1002/2015MS000568
出版社：John Wiley & Sons, Ltd.
摘要：Using highly resolved large‐eddy simulations on two different domain sizes, we investigate the influence of precipitation and spatial organization on the thermodynamic structure of the trade‐wind layer, under a uniform 4 K warming at constant relative humidity. In nonprecipitating simulations, the increased surface latent heat flux in the warmer climate produces a deeper and drier cloud layer with reduced cloud fractions between 1.5 and 4 km. Precipitation prevents the deepening and drying of the cloud layer in response to warming. Cloud fractions still decrease in the upper cloud layer, because stratiform outflow layers near cloud tops are less pronounced and because the larger liquid water contents are confined to narrower updrafts. Simulations on a 16‐fold larger domain lead to the spatial organization of clouds into larger and deeper cloud clusters. The presence of deeper clouds results in a shallower, warmer, and drier trade‐wind layer, with strongly reduced cloud cover. The warming response in the precipitating large‐domain simulation nevertheless remains similar to the small‐domain precipitating simulation. On the large domain, deeper clouds can also develop without precipitation, because moisture‐convection feedbacks strengthen in the absence of cold‐pool dynamics. Overall, total cloud cover and albedo decrease only slightly with warming in all cases. This demonstrates the robustness of shallow cumuli—in particular of cloud fraction near the lifting condensation level—to changes in the large‐scale environment.
关键词：marine boundary layer clouds;cloud feedback;large‐eddy simulation;convective organization