气候变化领域集成服务门户(CCPortal): La Niña's Diminishing Fingerprint on the Central Indian Summer Monsoon

CCPortal

DOI	10.1029/2019GL086237
	La Niña's Diminishing Fingerprint on the Central Indian Summer Monsoon
	Samanta D.; Rajagopalan B.; Karnauskas K.B.; Zhang L.; Goodkin N.F.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:2
英文摘要	La Niña years tend to provide increased Indian summer monsoon (ISM) rainfall. However, observations show 6–8% reduction in ISM rainfall during post-1980 La Niñas relative to pre-1980. Using a suite of atmospheric general circulation model experiments, we replicate this observed phenomenon and attribute it to a combination of weakening La Niña events themselves plus strongly warming tropical Indian Ocean. We demonstrate that half of the ISM rainfall reduction during post-1980 La Niñas can be attributed to changes in the spatial pattern and intensity of La Niña within the tropical Pacific Ocean. Warmer eastern-equatorial Pacific Ocean temperatures during post-1980 La Niñas weaken the Walker circulation, resulting in large-scale anomalous subsidence over the Indian subcontinent, thereby inhibiting the deep convection that drives ISM rainfall. Further, we demonstrate the declining central ISM rainfall during La Niña years with increasing tropical Indian Ocean warming, which has several serious concerns for regional water resources and stability. ©2020. The Authors.
英文关键词	Atmospheric thermodynamics; Rain; Tropics; Water resources; AGCM; Indian ocean; Teleconnections; tropical Pacific; Walker circulation; Oceanography; air-sea interaction; atmospheric convection; atmospheric general circulation model; La Nina; monsoon; rainfall; teleconnection; Indian Ocean; Indian Ocean (Tropical); Pacific Ocean; Pacific Ocean (Equatorial)
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170832
作者单位	Asian School of the Environment, Nanyang Technological University, Singapore; Department of Civil Environmental and Architectural Engineering, University of Colorado Boulder, Boulder, CO, United States; Cooperative Institute for Research in Environmental Science, University of Colorado Boulder, Boulder, CO, United States; Department of Atmospheric and Oceanic Sciences, University of Colorado Boulder, Boulder, CO, United States; Earth Observatory of Singapore, Singapore; Department of Earth and Planetary Sciences, American Museum of Natural History, New York City, NY, United States
推荐引用方式 GB/T 7714	Samanta D.,Rajagopalan B.,Karnauskas K.B.,et al. La Niña's Diminishing Fingerprint on the Central Indian Summer Monsoon[J],2020,47(2).
APA	Samanta D.,Rajagopalan B.,Karnauskas K.B.,Zhang L.,&Goodkin N.F..(2020).La Niña's Diminishing Fingerprint on the Central Indian Summer Monsoon.Geophysical Research Letters,47(2).
MLA	Samanta D.,et al."La Niña's Diminishing Fingerprint on the Central Indian Summer Monsoon".Geophysical Research Letters 47.2(2020).