文章基本信息

标题：On the influence of poleward jet shift on shortwave cloud feedback in global climate models
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作者：Casey J. Wall ; Dennis L. Hartmann
期刊名称：Journal of Advances in Modeling Earth Systems
电子版ISSN：1942-2466
出版年度：2015
卷号：7
期号：4
页码：2044-2059
DOI：10.1002/2015MS000520
出版社：John Wiley & Sons, Ltd.
摘要：Experiments designed to separate the effect of atmospheric warming from the effect of shifts of the eddy‐driven jet on shortwave (SW) cloud feedback are performed with three global climate models (GCMs). In each model a warming simulation produces a robust SW cloud feedback dipole, with a negative (positive) feedback in the high‐latitudes (subtropics). The cloud brightening in high‐latitudes that characterizes warming simulations is not produced by jet shifts alone in any of the models, but is highly sensitive to perturbations of freezing temperature seen by the cloud microphysics scheme, indicating that thermodynamic mechanisms involving the phase of cloud condensate dominate the SW feedback at high‐latitudes. In one of the models a poleward jet shift causes significant cloud dimming throughout the midlatitudes, but in two models it does not. Differences in cloud response to jet shifts in two of the models are attributed to differences in the shallow convection parameterizations.
关键词：cloud feedbacks