Changing Indian monsoon rainfall patterns under the recent warming period 2001–2018.

The temperature and moisture distribution over the Indian subcontinent are changing in recent decades with the accelerated global temperature rise. These changes in distribution result in shifting wet/dry and warm/cold zones within India. The differential warming rate over land and surrounding ocean determine intricate dynamics of the Indian summer monsoon (ISM) and make the Indian region a more susceptible towards drought and flood events. In recent time, the frequent flooding over northwest India viz., over Gujrat and southern Rajasthan is attributed to the weakening of prevailing heat-trough circulation (northerly wind) and gradual increase in the convective activity (enhanced moist static energy). The recent weakening of the southwesterly reduced transport of moisture leading to reduced rainfall over Indo-Gangetic Plain (IGP) and northeast India; while the strengthening of the same enhanced the moisture transport and hence the rainfall over northwest India. In addition, northward shift of the sinking airmass over equatorial region, in recent time, leads to the decrease of the rainfall over the southern Indian region. The recent changes in rainfall pattern have shifted the climate of IGP and northeast India towards the relatively arid regime and that of western India towards a relatively moist regime, which supports the possible greening of the Thar region. The recent change in rainfall distribution in the form of wet and dry zones across the country will impact the water resource, food security as well as the fragile local ecosystems. [ABSTRACT FROM AUTHOR]