Differential heating in the Indian Ocean differentially modulates precipitation in the Ganges and Brahmaputra basins

Remote Sensing
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Abstract

Indo-Pacific sea surface temperature dynamics play a prominent role in Asian summer monsoon variability. Two interactive climate modes of the Indo-Pacific—the El Niño/Southern Oscillation (ENSO) and the Indian Ocean dipole mode—modulate the amount of precipitation over India, in addition to precipitation over Africa, Indonesia, and Australia. However, this modulation is not spatially uniform. The precipitation in southern India is strongly forced by the Indian Ocean dipole mode and ENSO. In contrast, across northern India, encompassing the Ganges and Brahmaputra basins, the climate mode influence on precipitation is much less. Understanding the forcing of precipitation in these river basins is vital for food security and ecosystem services for over half a billion people. Using 28 years of remote sensing observations, we demonstrate that (i) the tropical west-east differential heating in the Indian Ocean influences the Ganges precipitation and (ii) the north-south differential heating in the Indian Ocean influences the Brahmaputra precipitation. The El Niño phase induces warming in the warm pool of the Indian Ocean and exerts more influence on Ganges precipitation than Brahmaputra precipitation. The analyses indicate that both the magnitude and position of the sea surface temperature anomalies in the Indian Ocean are important drivers for precipitation dynamics that can be effectively summarized using two new indices, one tuned for each basin. These new indices have the potential to aid forecasting of drought and flooding, to contextualize land cover and land use change, and to assess the regional impacts of climate change.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Differential heating in the Indian Ocean differentially modulates precipitation in the Ganges and Brahmaputra basins
Series title Remote Sensing
DOI 10.3390/rs8110901
Volume 8
Issue 11
Year Published 2016
Language English
Publisher MDPI
Contributing office(s) Earth Resources Observation and Science (EROS) Center
Description Article 901; 16 p.
First page 1
Last page 16
Other Geospatial Indian Ocean