DOI: 10.1007/s00382-014-2132-6
Scopus记录号: 2-s2.0-84905110615
论文题名: Role of the Indian Ocean sea surface temperature in shaping the natural variability in the flow of Nile River
作者: Siam M.S. ; Wang G. ; Demory M.-E. ; Eltahir E.A.B.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 43, 期: 2017-03-04 起始页码: 1011
结束页码: 1023
语种: 英语
英文关键词: ENSO
; Indian Ocean
; Nile
英文摘要: A significant fraction of the inter-annual variability in the Nile River flow is shaped by El Niño Southern Oscillation (ENSO). Here, we investigate a similar role for the Indian Ocean (IO) sea surface temperature (SST) in shaping the inter-annual variability of the Nile River flow. Using observations of global SST distribution and river flow in addition to atmospheric general circulation model sensitivity experiments, we show that North and Middle IO SSTs play a significant intermediate role in the teleconnection between ENSO and the Nile flow. Applying partial coherency analyses, we demonstrate that the connection between North and Middle IO SSTs and Nile flow is strongly coupled to ENSO. During El Niño events, SST in the North and Middle IO increases in response to the warming in the Tropical Eastern Pacific Ocean and forces a Gill-type circulation with enhanced westerly low-level flow over East Africa and the Western IO. This anomalous low-level flow enhances the low-level flux of air and moisture away from the Upper Blue Nile (UBN) basin resulting in reduction of rainfall and river flow. SSTs in the South IO also play a significant role in shaping the variability of the Nile flow that is independent from ENSO. A warming over the South IO, generates a cyclonic flow in the boundary layer, which reduces the cross-equatorial meridional transport of air and moisture towards the UBN basin, favoring a reduction in rainfall and river flow. This independence between the roles of ENSO and South IO SSTs allows for development of new combined indices of SSTs to explain the inter-annual variability of the Nile flow. The proposed teleconnections have important implications regarding mechanisms that shape the regional impacts of climate change over the Nile basin. © 2014 Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54609
Appears in Collections: 过去全球变化的重建
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作者单位: Ralph M. Parsons Laboratory, Massachusetts Institute of Technology, 15 Vassar St., Cambridge, MA, 02139, United States; Department of Civil and Environmental Engineering, Center for Environmental Sciences and Engineering, University of Connecticut, Storrs, CT, United States; National Centre for Atmospheric Science, Department of Meteorology, University of Reading, Reading, United Kingdom
Recommended Citation:
Siam M.S.,Wang G.,Demory M.-E.,et al. Role of the Indian Ocean sea surface temperature in shaping the natural variability in the flow of Nile River[J]. Climate Dynamics,2014-01-01,43(2017-03-04)