Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1007/s00382-020-05577-9
Licence creative commons licence
Title (Primary) Dual response of Arabian Sea cyclones and strength of Indian monsoon to Southern Atlantic Ocean
Author Hari, V.; Pathak, A.; Koppa, A.
Journal Climate Dynamics
Year 2021
Department CHS
Volume 56
Issue 7-8
Page From 2149
Page To 2161
Language englisch
Topic T5 Future Landscapes
Keywords Arabian Sea cyclones; Indian summer monsoon rainfall; South Atlantic Ocean
Abstract Variability and trends of the south Asian monsoon at different time scales makes the region susceptible to climate-related natural disasters such as droughts and floods. Because of its importance, different studies have examined the climatic factors responsible for the recent changes in monsoon strength. Here, using observations and climate model experiments we show that monsoon strength is driven by the variations of south Atlantic Ocean sea surface temperature (SASST). The mechanism by which SASST is modulating the monsoon could be explained through the classical Matsuno-Gill response, leading to changes in the characteristics of vertical wind shear in the Arabian Sea. The decline in the vertical wind shear to the warming of SASST is associated with anomalous lower (upper)-level easterlies (westerlies). This further leads to a strong increase in the frequency of the Arabian Sea cyclones; and also prohibits the transport of moisture to the Indian landmass, which eventually reduces the strength of monsoon. The conditions in the SASST which drove these responses are aggravated by greenhouse gas emission, revealing the prominent role played by anthropogenic warming. If, with proper mitigation, these emissions are not prevented, further increases in the SASST is expected to result in increased Arabian sea cyclones and reduced monsoon strength.
Persistent UFZ Identifier
Hari, V., Pathak, A., Koppa, A. (2021):
Dual response of Arabian Sea cyclones and strength of Indian monsoon to Southern Atlantic Ocean
Clim. Dyn. 56 (7-8), 2149 - 2161