气候变化领域集成服务门户(CCPortal): ENSO teleconnection to eastern african summer rainfall in global climate models: Role of the tropical easterly jet

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DOI	10.1175/JCLI-D-20-0222.1
	ENSO teleconnection to eastern african summer rainfall in global climate models: Role of the tropical easterly jet
	Vashisht A.; Zaitchik B.; Gnanadesikan A.
发表日期	2021
ISSN	0894-8755
起始页码	293
结束页码	312
卷号	34 期号:1
英文摘要	Global climate models (GCMs) are critical tools for understanding and projecting climate variability and change, yet the performance of these models is notoriously weak over much of tropical Africa. To improve this situation, process-based studies of African climate dynamics and their representation in GCMs are required. Here, we focus on summer rainfall of eastern Africa (SREA), which is crucial to the Ethiopian Highlands and feeds the flow of the Blue Nile River. The SREA region is highly vulnerable to droughts, with El Niño-Southern Oscillation (ENSO) being a leading cause of interannual rainfall variability. Adequate understanding and accurate representation of climate features that influence regional variability is an important but often neglected issue when evaluating models. We perform a process-based evaluation of GCMs, focusing on the upper-troposphere tropical easterly jet (TEJ), which has been hypothesized to link ENSO to SREA. We find that most models have an ENSO-TEJ coupling similar to observed, but the models diverge in their representation of TEJ-SREA coupling. Differences in the latter explain the majority (80%) of variability in ENSO teleconnection simulation across the models. This is higher than the variance explained by rainfall coupling with the Somali jet (44%) and African easterly jet (55%). However, our diagnostics of the leading hypothesized mechanism in the models-variability in divergence in the TEJ exit region-are not consistent across models and suggest that a deeper understanding of the mechanisms of TEJ-precipitation coupling should be a priority for studies of climate variability and change in the region. © 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	Atmospheric pressure; Climate change; Rain; Tropics; African easterly jet; Climate variability and change; Global climate model; Interannual rainfall; Regional variability; Southern oscillation; Tropical Easterly Jet; Tropical easterly jets; Climate models; climate change; climate variation; easterly wave; El Nino-Southern Oscillation; jet; precipitation intensity; seasonal variation; teleconnection; Blue Nile [Nile River]; Nile River
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/170979
作者单位	Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, United States
推荐引用方式 GB/T 7714	Vashisht A.,Zaitchik B.,Gnanadesikan A.. ENSO teleconnection to eastern african summer rainfall in global climate models: Role of the tropical easterly jet[J],2021,34(1).
APA	Vashisht A.,Zaitchik B.,&Gnanadesikan A..(2021).ENSO teleconnection to eastern african summer rainfall in global climate models: Role of the tropical easterly jet.Journal of Climate,34(1).
MLA	Vashisht A.,et al."ENSO teleconnection to eastern african summer rainfall in global climate models: Role of the tropical easterly jet".Journal of Climate 34.1(2021).