气候变化领域集成服务门户(CCPortal): Northeast monsoon rainfall variability over the southern Peninsular India associated with multiyear La Niña events

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DOI	10.1007/s00382-019-04927-6
	Northeast monsoon rainfall variability over the southern Peninsular India associated with multiyear La Niña events
	Prasanna K.; Singh P.; Chowdary J.S.; Naidu C.V.; Parekh A.; Gnanaseelan C.; Dandi R.
发表日期	2019
ISSN	0930-7575
起始页码	6265
结束页码	6291
卷号	53 期号:2020-09-10
英文摘要	The present study examines the variability of Northeast Monsoon (NEM) rainfall over the southern Peninsular India (SPI) associated with multiyear-La Niña events using observations and Coupled Model Inter-comparison Project Phase 5 (CMIP5) models. The analysis is carried out for NEM season (October–December) of two successive La Niña years, referred to as the first and second year during the period 1900–2010. Observations show that despite noticeable weakening in the equatorial Pacific cooling from the first year to the second year, strong La Niña teleconnections and the rainfall deficiency over the SPI region remains the same in most of the multiyear-La Niña events (70%). In the first year, zonally protracted low level cyclonic circulation over the north Indian Ocean (NIO) region induces northwesterly wind anomalies over SPI region. Negative moisture anomalies corroborated by northwesterlies and subsidence cause deficient rainfall over this region. On the other hand, the western flank of NIO cyclonic circulation is pushed towards Indian longitudes in the second year, inducing dry northerlies over SPI region. Development of low level divergent flow over the western tropical Indian Ocean and eastward migration of convergence zone from Bay of Bengal are found to be responsible for the shift in circulation pattern. These anomalous circulations together with low moisture content are responsible for deficit NEM rainfall in the second year. Differences in circulation patterns noted in the first and second year are associated with changes in the La Niña related SST patterns over the equatorial Pacific and modulation of the upper/lower level convergence/divergence zones. Analysis reveals that most of the CMIP5 models have tendency to simulate excess rainfall over the SPI region (in 70–100% of multiyear-La Niña events) unlike in the observations (30% of events). The possible reasons for the simulation of such positive rainfall anomalies are explored in the present study. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	ENSO teleconnections; Multiyear La Niña events; Northeast monsoon; Precipitation; Sea Surface Temperature
语种	英语
scopus关键词	air-sea interaction; climate modeling; convergence; El Nino-Southern Oscillation; La Nina; monsoon; rainfall; sea surface temperature; teleconnection; Bay of Bengal; India; Indian Ocean; Indian Ocean (Tropical); Pacific Ocean; Pacific Ocean (Equatorial)
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/145876
作者单位	Department of Meteorology and Oceanography, College of Science and Technology, Andhra University, Visakhapatnam, 530 003, India; Indian Institute of Tropical Meteorology, Pune, 411 008, India
推荐引用方式 GB/T 7714	Prasanna K.,Singh P.,Chowdary J.S.,et al. Northeast monsoon rainfall variability over the southern Peninsular India associated with multiyear La Niña events[J],2019,53(2020-09-10).
APA	Prasanna K..,Singh P..,Chowdary J.S..,Naidu C.V..,Parekh A..,...&Dandi R..(2019).Northeast monsoon rainfall variability over the southern Peninsular India associated with multiyear La Niña events.Climate Dynamics,53(2020-09-10).
MLA	Prasanna K.,et al."Northeast monsoon rainfall variability over the southern Peninsular India associated with multiyear La Niña events".Climate Dynamics 53.2020-09-10(2019).