气候变化领域集成服务门户(CCPortal): Future evolution of the Sahel precipitation zonal contrast in CESM1

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DOI	10.1007/s00382-020-05417-w
	Future evolution of the Sahel precipitation zonal contrast in CESM1
	Monerie P.-A.; Sanchez-Gomez E.; Gaetani M.; Mohino E.; Dong B.
发表日期	2020
ISSN	0930-7575
起始页码	2801
结束页码	2821
卷号	55
英文摘要	The main focus of this study is the zonal contrast of the Sahel precipitation shown in the CMIP5 climate projections: precipitation decreases over the western Sahel (i.e., Senegal and western Mali) and increases over the central Sahel (i.e., eastern Mali, Burkina Faso and Niger). This zonal contrast in future precipitation change is a robust model response to climate change but suffers from a lack of an explanation. To this aim, we study the impact of current and future climate change on Sahel precipitation by using the Large Ensemble of the Community Earth System Model version 1 (CESM1). In CESM1, global warming leads to a strengthening of the zonal contrast, as shown by the difference between the 2060–2099 period (under a high emission scenario) and the 1960–1999 period (under the historical forcing). The zonal contrast is associated with dynamic shifts in the atmospheric circulation. We show that, in absence of a forced response, that is, when only accounting for internal climate variability, the zonal contrast is associated with the Pacific and the tropical Atlantic oceans variability. However, future patterns in sea surface temperature (SST) anomalies are not necessary to explaining the projected strengthening of the zonal contrast. The mechanisms underlying the simulated changes are elucidated by analysing a set of CMIP5 idealised simulations. We show the increase in precipitation over the central Sahel to be mostly associated with the surface warming over northern Africa, which favour the displacement of the monsoon cell northwards. Over the western Sahel, the decrease in Sahel precipitation is associated with a southward shift of the monsoon circulation, and is mostly due to the warming of the SST. These two mechanisms allow explaining the zonal contrast in precipitation change. © 2020, The Author(s).
英文关键词	Climate change; Internal climate variability; Large ensemble; Sahel precipitation; Sahel zonal contrast
语种	英语
scopus关键词	climate change; climate variation; CMIP; computer simulation; ensemble forecasting; monsoon; precipitation assessment; sea surface temperature; zonal flow; Sahel [Sub-Saharan Africa]
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/145280
作者单位	National Centre for Atmospheric Science (NCAS), Department of Meteorology, University of Reading, Reading, United Kingdom; CECI, UMR 5318, CERFACS/CNRS, Toulouse, France; Scuola Universitaria Superiore IUSS, Pavia, Italy; Dpto. Física de la Tierra y Astrofísica, Facultad Ciencias Físicas, Universidad Complutense de Madrid, Ciudad Universitaria, Plaza Ciencias, Madrid, 28040, Spain
推荐引用方式 GB/T 7714	Monerie P.-A.,Sanchez-Gomez E.,Gaetani M.,et al. Future evolution of the Sahel precipitation zonal contrast in CESM1[J],2020,55.
APA	Monerie P.-A.,Sanchez-Gomez E.,Gaetani M.,Mohino E.,&Dong B..(2020).Future evolution of the Sahel precipitation zonal contrast in CESM1.Climate Dynamics,55.
MLA	Monerie P.-A.,et al."Future evolution of the Sahel precipitation zonal contrast in CESM1".Climate Dynamics 55(2020).