IIOSC - 2025

IIOSC - 2025

International Indian Ocean Science Conference - 2025

Celebrating 10 years of the Second International Indian Ocean Expedition

01-05 December 2025
INCOIS, Hyderabad, India.

Summary of Abstract Submission



Abstract Submission No.ABS-04-0191
Title of AbstractRising Frequency of Yangtze River Floods Linked to Shifts in the Indian Ocean Wave Characteristics
AuthorsPanini Dasgupta*, SungHyun Nam, Michael J. McPhaden, Dong-Jin Kang, M. K. Roxy, Saranya J S
OrganisationSeoul National University
Address1 Gwanak-ro, Gwanak-gu, Seoul, Republic of Korea
Seoul, Seoul, Korea, Rep.
Pincode: 08826
E-mail: panini@snu.ac.kr
CountryKorea, Rep.
PresentationOral
AbstractIn recent decades, particularly since the 1990s, the frequency of flood events in the Yangtze River Basin has increased significantly. This rise in hydroclimatic extremes is closely linked to enhanced variability at the quasi-biennial (QB) timescale. In this study, using sea surface height (SSH) and thermocline depth data from the ORAS5 reanalysis and the EN4 observational analysis, we demonstrate that the increased QB variability in East Asian summer monsoon rainfall over the Yangtze River Basin is strongly coupled with intensified QB-scale wave dynamics in the Indian Ocean. We present strong evidence of fundamental changes in the characteristics of baroclinic waves in the tropical Indian Ocean in recent decades. We find that the mean phase speed of westward-propagating tropical Rossby waves has increased, along with their overall variance. These shifts are likely associated with changes in oceanic circulation and large-scale atmospheric forcing. Our findings highlight that evolving Indian Ocean wave dynamics is a key contributor to the amplification of monsoon variability and the associated hydrological extremes over East Asia.
Are you part of IIOE-2 endorsed projectyes
Endorsed Project NumberIIOE2-EP51
KeywordsYangtze River Discharge, Quasi-biennial,Tropical Rossby Waves
For Awardsyes
Date Of Birth18-04-1991
ECSN Registration NumberIIOE2-ECSN-0138