By Shreeshan Venkatesh
The Indian summer monsoon has changed. Successively unpredictable and volatile monsoons have ratcheted up the spectre of a “new normal” in monsoons- an alternating assault of extreme rain and absolutely none. However, evidence for this change that is underway and its pathways is still being put together. Research published today in Nature Communications goes some way in explaining the newfound extreme nature of our monsoons. The study finds that widespread extreme rain events over central India have increased three-fold in the 66-year period between 1950 and 2015. The study notes a 10-30 per cent increase in rainfall events over the region where more than 150 mm of rain is registered in a day has been occurring despite a general weakening of monsoon circulation.
According to the paper, while monsoon rainfall over central India from June-September has decreased by about 10 per cent during the study period, the frequency of extreme rain events has increased by a staggering 75 per cent, indicating a rate of increase of more than one event per year. While this may not seem like much at first sight, the cumulative effect of such a trend over a long period of time is likely to be devastating.
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