Disentangling increasing compound extremes at regional scale during
Indian Summer Monsoon
Abstract
Compound extremes exhibit greater adverse impacts than their univariate
counterparts. Studies have reported changes in frequency and the spatial
extent of extremes in India; however, investigation of compound extremes
is in the infancy state. This study investigates the historical
variation of compound dry and hot extremes (CDHE) and compound wet and
cold extremes (CWCE) during the Indian summer monsoon period from
1951-2019 using monthly data. Results are analyzed for 10 identified
homogeneous regions for India. Our results unraveled that CDHE (CWCE)
frequency has increased (decreased) by 1-3 events per decade for the
recent period (1977-2019) relative to the base period (1951-1976).
Overall, there is increasing (decreasing) pattern of CDHE (CWCE) is high
across North-central India, Western India, North-eastern India and
South-eastern coastlines. Our findings help in identification of the
parts of the country were affected by frequent and widespread CDHE
during the recent period, which is alarming. More detailed assessments
are required to disentangle the complex physical process of compound
extremes to improve risk management options.