Congo Basin drying associated with poleward shifts of the African thermal lows

doi:10.1007/s00382-019-05033-3

	Congo Basin drying associated with poleward shifts of the African thermal lows
	Cook, Kerry H.1; Liu, Yang 1,2; Vizy, Edward K.1
刊名	CLIMATE DYNAMICS
	2019-11-06
页码	21
关键词	Central Equatorial Africa Congo Basin rainforest Tropical forest change African precipitation trends Angola low Tropical expansion
ISSN号	0930-7575
DOI	10.1007/s00382-019-05033-3
通讯作者	Cook, Kerry H.(kc@jsg.utexas.edu)
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.
资助项目	NSF[1356386]
WOS关键词	SOIL-MOISTURE ; PART II ; PRECIPITATION ; EQUATORIAL ; CIRCULATION ; CLIMATE ; RAINFALL ; SAHEL ; SEASONALITY ; VARIABILITY
WOS研究方向	Meteorology & Atmospheric Sciences
语种	英语
出版者	SPRINGER
WOS记录号	WOS:000494426900003
资助机构	NSF
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/131786]
专题	中国科学院地理科学与资源研究所
通讯作者	Cook, Kerry H.
作者单位	1.Univ Texas Austin, Jackson Sch Geosci, Dept Geol Sci, Austin, TX 78712 USA 2.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Land Surface Pattern & Simulat, Beijing 100101, Peoples R China
推荐引用方式 GB/T 7714	Cook, Kerry H.,Liu, Yang,Vizy, Edward K.. Congo Basin drying associated with poleward shifts of the African thermal lows[J]. CLIMATE DYNAMICS,2019:21.
APA	Cook, Kerry H.,Liu, Yang,&Vizy, Edward K..(2019).Congo Basin drying associated with poleward shifts of the African thermal lows.CLIMATE DYNAMICS,21.
MLA	Cook, Kerry H.,et al."Congo Basin drying associated with poleward shifts of the African thermal lows".CLIMATE DYNAMICS (2019):21.