DOI: 10.1007/s00382-016-2999-5
Scopus记录号: 2-s2.0-84991287232
论文题名: Combined influence of remote and local SST forcing on Indian Summer Monsoon Rainfall variability
作者: Chakravorty S. ; Gnanaseelan C. ; Pillai P.A.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2016
卷: 47, 期: 2017-09-10 起始页码: 2817
结束页码: 2831
语种: 英语
英文关键词: El Nino
; Epochal changes
; Indian monsoon
; Indian Ocean
; Keywords
; North Pacific circulation
英文摘要: The combined influence of tropical Indian Ocean (TIO) and Pacific Ocean (TPO) sea surface temperature (SST) anomalies on Indian summer monsoon rainfall (ISMR) variability is studied in the context of mid-1970s regime shift. The rainfall pattern on the various stages of monsoon during the developing and decaying summer of El Niño is emphasized. Analysis reveals that ISMR anomalies during El Niño developing summer in epoch-1 (1950–1979) are mainly driven by El Niño forcing throughout the season, whereas TIO SST exhibits only a passive influence. On the other hand in epoch-2 (1980–2009) ISMR does not show any significant relation with Pacific during the onset phase of monsoon whereas withdrawal phase is strongly influenced by El Niño. Again the eastern Indian Ocean cooling and westward shift in northwest Pacific (NWP) cyclonic circulation during epoch-2 have strong positive influence on the rainfall over the central and eastern India during the matured phase of monsoon. ISMR in the El Niño decaying summer does not show any significant anomalies in epoch-1 as both Pacific and Indian Ocean warming dissipate by the summer. On the other hand in epoch-2 ISMR anomalies are significant and display strong variability throughout the season. In the onset phase of monsoon, central and east India experience strong negative precipitation anomalies due to westward extension of persistent NWP anticyclone (forced by persisting Indian Ocean warming). The persistent TIO warming induces positive precipitation anomalies in the withdrawal phase of monsoon by changing the atmospheric circulation and modulating the water vapour flux. Moisture budget analysis unravels the dominant processes responsible for the differences between the two epochs. The moisture convergence and moisture advection are very weak (strong) over Indian land mass during epoch-1 (epoch-2) in El Niño decaying summer. The changing moisture availability and convergence play important role in explaining the weakening of ENSO monsoon relation in the recent years. The local TIO SST forcing and NWP circulation are prominent forcing factors for the interannual variability of ISMR during epoch-2. © 2016, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53489
Appears in Collections: 过去全球变化的重建
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作者单位: Indian Institute of Tropical Meteorology, Pune, India
Recommended Citation:
Chakravorty S.,Gnanaseelan C.,Pillai P.A.. Combined influence of remote and local SST forcing on Indian Summer Monsoon Rainfall variability[J]. Climate Dynamics,2016-01-01,47(2017-09-10)