Research Highlight

Severe rainfall predicted over South India, Himalayan foothills in coming years

doi:10.1038/nindia.2020.135 Published online 9 September 2020

Researchers from the Indian Institute of Technology (IIT) in Kharagpur have found that patterns of Indian Summer Monsoon Rainfall (ISMR) have been changing for more than four decades1. According to them, ISMR is expected to further intensify over southern India and the Himalayan foothills.

They have also predicted a continued southward shift of rainfall extremes over South Asia, particularly in the countries such as Myanmar, Thailand and Malaysia. 

The researchers say such future changes in rainfall patterns are influenced by human factors such as population growth and man-made emissions of greenhouse gases that potentially contribute to climate change. 

To understand the past and future changes in ISMR, the IIT scientists analysed daily rainfall patterns during monsoon and post-monsoon periods between 1971 and 2017.   

They found an increase in extreme rainfall over south India compared with north and central India during 1971–2017.

Next, the researchers studied the future patterns of ISMR over South Asia for the entire period between 2006 and 2100. They used data on rainfall patterns and other factors such as moisture flux and convergence that contribute to rainfall from the CORDEX (Coordinated Regional Climate Downscaling Experiment), designed to generate regional-scale climate projections.  

The mean daily rainfall, they report, is likely to increase in most parts of South Asia and the Indian Ocean. However, it will decrease slightly in western Asia, parts of the Indian Ocean near Indonesia, and in north and central India.


References

1. Suman, M. et al. Southward shift of precipitation extremes over South Asia: evidences from CORDEX data. Sci. Rep.10, 6452 (2020)