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Indian monsoon derailed by a North Atlantic wavetrain

Borah, PJ and Venugopal, V and Sukhatme, J and Muddebihal, P and Goswami, BN (2020) Indian monsoon derailed by a North Atlantic wavetrain. In: Science, 370 (6522). pp. 1335-1338.

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Official URL: https://dx.doi.org/10.1126/science.aay6043


The forecast of Indian monsoon droughts has been predicated on the notion of a season-long rainfall deficit linked to a warm equatorial Pacific. Here we show that nearly half of all droughts over the past century differ from this paradigm in that they (i) occur when Pacific temperatures are near-neutral and (ii) are subseasonal phenomena, characterized by an abrupt decline in late-season rainfall. This severe subseasonal rainfall deficit can be associated with a Rossby wave from mid-latitudes. Specifically, we find that the interaction of upper-level winds with an episodic North Atlantic vorticity anomaly results in a wavetrain that curves toward East Asia, disrupting the monsoon. This atmospheric teleconnection offers an avenue for improved predictability of droughts, especially in the absence of telltale signatures in the Pacific. © 2020 American Association for the Advancement of Science. All rights reserved.

Item Type: Journal Article
Publication: Science
Publisher: American Association for the Advancement of Science
Additional Information: Copyright to this article belongs to American Association for the Advancement of Science
Department/Centre: Division of Mechanical Sciences > Divecha Centre for Climate Change
Division of Interdisciplinary Sciences > Interdisciplinary Centre for Water Research
Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited: 11 Feb 2021 10:25
Last Modified: 11 Feb 2021 10:25
URI: http://eprints.iisc.ac.in/id/eprint/67523

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