Large-Scale Extreme Rainfall-Producing Synoptic Systems of the Indian Summer Monsoon

Nikumbh, AC and Chakraborty, A and Bhat, GS and Frierson, DMW (2020) Large-Scale Extreme Rainfall-Producing Synoptic Systems of the Indian Summer Monsoon. In: Geophysical Research Letters, 47 (11).

PDF Lar_sca_ext_rai_syn_sys_pdf_2024 - Published Version Download (13MB)

Abstract

In recent years India has been increasingly experiencing widespread floods induced by large-scale extreme rainfall events (LEREs). LEREs are mainly associated with monsoon low-pressure systems (LPS). The forecast of these high-flood-potential events, however, has remained challenging. Here, we compare LPSs of the summer monsoon that led to LEREs (LPS-Lg) and strong LPSs that did not result in LEREs (LPS-noLg) over central India for the period 1979�2012. We show that having a strong LPS is not a sufficient condition to produce LEREs, and the LPS-Lgs are accompanied by secondary cyclonic vortices (SCVs). The simultaneous existence of an LPS and an SCV creates a giant midtropospheric vortex. SCVs enhance dynamic lifting, static instability, and moisture transport from the Arabian Sea that precondition the atmosphere for deep convection. SCVs also slow down the propagation of LPSs. We show that the interaction of synoptic-scale systems can lead to LEREs even if individual systems are not strong enough. ©2020. American Geophysical Union. All Rights Reserved.

Item Type:	Journal Article
Publication:	Geophysical Research Letters
Publisher:	Blackwell Publishing Ltd
Additional Information:	The copyrights for this article belongs to authors.
Keywords:	Atmospheric thermodynamics; Floods; Rain; Vortex flow, Cyclonic vortices; Indian summer monsoon; Individual systems; Low pressure systems; Moisture transport; Static instability; Synoptic systems; Synoptic-scale systems, Flood control, convection; extreme event; low pressure system; monsoon; precipitation intensity; summer, Arabian Sea; India; Indian Ocean, Strawberry crinkle virus
Department/Centre:	Division of Mechanical Sciences > Divecha Centre for Climate Change Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	19 Dec 2024 11:15
Last Modified:	19 Dec 2024 11:15
URI:	http://eprints.iisc.ac.in/id/eprint/65800

Actions (login required)

View Item