气候变化领域集成服务门户(CCPortal): Congo Basin drying associated with poleward shifts of the African thermal lows

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DOI	10.1007/s00382-019-05033-3
	Congo Basin drying associated with poleward shifts of the African thermal lows
	Cook K.H.; Liu Y.; Vizy E.K.
发表日期	2020
ISSN	0930-7575
起始页码	863
结束页码	883
卷号	54 期号:2020-01-02
英文摘要	Trends in Congo Basin rainfall in six observational datasets are examined on monthly and annual time scales to motivate an investigation of changes in the atmospheric hydrodynamics. Annual-mean Congo Basin rainfall declines over the 1979–2017 time period in all datasets, with strongest agreement and statistical significance from March through August. The trends are less pronounced over the 1998–2017 time period, especially for boreal spring, with although the boreal summer season continues to dry. Decadal-scale differences in the atmospheric hydrodynamics are examined in three reanalyses to improve our physical understanding of the precipitation trends and add confidence. During much of the spring and fall, changes in the atmospheric circulation reflect regional processes and feedbacks. During the warm season in each hemisphere, Congo Basin precipitation is supported when the circulation about continental thermal lows converges with cross-equatorial flow from the winter hemisphere. The drying trend during these seasons is associated with poleward shifts of the continental thermal lows, which weakens this convergence. Rainfall anomalies are not directly related to local surface warming, and they do not involve modifications of moisture transport from the Atlantic or Indian Oceans. For boreal summer, the drying is related to amplified warming over the Sahara. In austral summer, a southward shift of the thermal low is part of a large-scale, zonal mean pattern shifting the subtropical highs poleward. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	African precipitation trends; Angola low; Central Equatorial Africa; Congo Basin rainforest; Tropical expansion; Tropical forest change
语种	英语
scopus关键词	annual variation; hydrodynamics; precipitation assessment; rainfall; rainforest; river basin; trend analysis; tropical environment; tropical forest; Angola; Congo Basin
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/145786
作者单位	Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, TX 78712, United States; Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
推荐引用方式 GB/T 7714	Cook K.H.,Liu Y.,Vizy E.K.. Congo Basin drying associated with poleward shifts of the African thermal lows[J],2020,54(2020-01-02).
APA	Cook K.H.,Liu Y.,&Vizy E.K..(2020).Congo Basin drying associated with poleward shifts of the African thermal lows.Climate Dynamics,54(2020-01-02).
MLA	Cook K.H.,et al."Congo Basin drying associated with poleward shifts of the African thermal lows".Climate Dynamics 54.2020-01-02(2020).