ENSO-monsoon relationships in a greenhouse warming scenario

• Published in: Geophysical research letters Vol. 28; no. 9; pp. 1727 - 1730
• Main Authors: Ashrit, R. G., Kumar, K. Rupa, Kumar, K. Krishna
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 01.05.2001; American Geophysical Union
• Subjects: Climatology. Bioclimatology. Climate change; Earth, ocean, space; Exact sciences and technology; External geophysics; Meteorology; Asia; India; Indian Ocean; ISW, Indian Ocean; Warming; Rain; Greenhouse effect; El Nino; General circulation models; Climatic data; Southern oscillation; Numerical simulation; Climate modification; Summer monsoon; La Nina; Interannual variation
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2000GL012489

Recent studies based on observed climatic data indicate weakening of the relationship between El Niño‐Southern Oscillation (ENSO) and Indian summer monsoon rainfall, possibly due to global warming. Transient climate change simulations of a coupled ocean‐atmosphere GCM (ECHAM4/OPYC3) project a change towards enhanced ENSO activities in the tropical Pacific, as well as increase in mean monsoon rainfall and variability over India. However, the interannual correlations between the two are strong throughout the 240 year simulation. Analysis of monsoon viz‐a‐viz ENSO in the model simulations suggest a diminished impact of warm ENSO (El Niño) events on monsoon, while the impact of cold ENSO (La Niña) events remains unchanged in the scenario. Anomalous warming over the Eurasian landmass as well as enhanced moisture conditions over the Indian monsoon region in the global warming scenario have possibly contributed to the weakening of the impact of warm ENSO events on monsoon.