The extreme positive Indian Ocean Dipole of 2019 and associated Indian summer monsoon rainfall response

Ratna, Satyaban B. ORCID: https://orcid.org/0000-0001-8780-8165, Cherchi, Annalisa, Osborn, Timothy J. ORCID: https://orcid.org/0000-0001-8425-6799, Joshi, Manoj ORCID: https://orcid.org/0000-0002-2948-2811 and Uppara, Umakanth ORCID: https://orcid.org/0000-0003-4872-967X (2021) The extreme positive Indian Ocean Dipole of 2019 and associated Indian summer monsoon rainfall response. Geophysical Research Letters, 48 (2). ISSN 0094-8276

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Abstract

The positive Indian Ocean Dipole (IOD) event in 2019 was among the strongest on record, while the Indian Summer monsoon (ISM) was anomalously dry in June then very wet by September. We investigated the relationships between the IOD, Pacific sea surface temperature (SST) and ISM rainfall during 2019 with an atmospheric general circulation model forced by observed SST anomalies. The results show that the extremely positive IOD was conducive to a wetter-than-normal ISM, especially late in the season when the IOD strengthened and was associated with anomalous low-level divergence over the eastern equatorial Indian Ocean and convergence over India. However, a warm SST anomaly in the central equatorial Pacific contributed to low level divergence and decreased rainfall over India in June. These results help to better understand the influence of the tropical SST anomalies on the seasonal evolution of ISM rainfall during extreme IOD events.

Item Type:	Article
Uncontrolled Keywords:	enso,indian ocean dipole,indian summer monsoon,climate variability,sea surface temperature,teleconnections,geophysics,earth and planetary sciences(all) ,/dk/atira/pure/subjectarea/asjc/1900/1908
Faculty \ School:	Faculty of Science > School of Environmental Sciences University of East Anglia Research Groups/Centres > Theme - ClimateUEA
UEA Research Groups:	Faculty of Science > Research Groups > Climatic Research Unit Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences Faculty of Social Sciences > Research Centres > Water Security Research Centre University of East Anglia Schools > Faculty of Science > Tyndall Centre for Climate Change Research Faculty of Science > Research Centres > Tyndall Centre for Climate Change Research
Related URLs:	http://www.scopus.com/inward/record.url?...
Depositing User:	LivePure Connector
Date Deposited:	17 Dec 2020 00:53
Last Modified:	04 Apr 2024 01:06
URI:	https://ueaeprints.uea.ac.uk/id/eprint/77990
DOI:	10.1029/2020GL091497

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