气候变化领域集成服务门户(CCPortal): Coupled climate model simulation of tropical–extratropical cloud bands over Southern Africa

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DOI	10.1175/JCLI-D-19-0731.1
	Coupled climate model simulation of tropical–extratropical cloud bands over Southern Africa
	James R.; Hart N.C.G.; Munday C.; Reason C.J.C.; Washington R.
发表日期	2020
ISSN	0894-8755
起始页码	8579
结束页码	8602
卷号	33 期号:19
英文摘要	There are increasing efforts to use climate model output for adaptation planning, but meanwhile there is often limited understanding of how models represent regional climate. Here we analyze the simulation in global coupled climate models of a key rainfall-generating mechanism over southern Africa: tropical temperate troughs (TTTs). An image-processing algorithm is applied to outgoing longwave radiation data from satellites and models to create TTT event sets. All models investigated produce TTTs with similar circulation features to observed. However, there are large differences among models in the number, intensity, and preferred longitude of events. Five groups of models are identified. The first group generates too few TTTs, and relatively dry conditions over southern Africa compared to other models. A second group generates more TTTs and wet biases. The contrast between these two groups suggests that the number of TTTs could explain intermodel variations in climatological rainfall. However, there is a third group of models that simulate up to 92% more TTTs than observed, but do not have large rainfall biases, as each TTT event is relatively weak. Finally, there are a further two groups that concentrate TTTs over the subcontinent or the ocean, respectively. These distinctions between models are associated with the amount of convective activity in the Congo Basin, the magnitude of moisture fluxes into southern Africa, and the degree of zonal asymmetry in upper-level westerly flow. Model development focused on tropical convection and the representation of orography is needed for improved simulation of TTTs, and therefore southern African rainfall. Ó 2020 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
英文关键词	Image processing; Rain; Tropics; American meteorological societies; Convective activity; Copyright informations; Coupled climate model; Generating mechanism; Image processing algorithm; Outgoing longwave radiation; Tropical convection; Climate models; climate modeling; climatology; cloud; longwave radiation; rainfall; regional climate; Congo Basin; Southern Africa; Satellites
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171109
作者单位	Climate Research Lab, Oxford University Centre for the Environment, Oxford, United Kingdom; Department of Oceanography, University of Cape Town, Cape Town, South Africa; Climate Research Lab, Oxford University Centre for the Environment, Oxford, United Kingdom
推荐引用方式 GB/T 7714	James R.,Hart N.C.G.,Munday C.,等. Coupled climate model simulation of tropical–extratropical cloud bands over Southern Africa[J],2020,33(19).
APA	James R.,Hart N.C.G.,Munday C.,Reason C.J.C.,&Washington R..(2020).Coupled climate model simulation of tropical–extratropical cloud bands over Southern Africa.Journal of Climate,33(19).
MLA	James R.,et al."Coupled climate model simulation of tropical–extratropical cloud bands over Southern Africa".Journal of Climate 33.19(2020).