Monsoon in north-central India can drop significantly: US scientific agency

Rainfall in north-central India can drop significantly this year because of the projected reduction in monsoon low-pressure system, according to a study of an American scientific agency.

The study by the National Oceanic and Atmospheric Administration (NOAA), released on Friday, projected a significant decrease in Monsoon Low-Pressure System (MLPS) occurrence over the south Asian monsoon region, attributed mainly to a reduction in low-level relative vorticity over the core genesis region.

Notably, MLPSs are the primary rain-producing synoptic-scale systems over the Indian subcontinent, and are estimated to be responsible for more than half of the annual precipitation in agrarian north and central India. Changes in the characteristics of MLPSs, whether natural or forced, have far-reaching socio-economic impacts, the NOAA said.

Despite increases in the total precipitation across much of the monsoon region, the model simulates little change or even slight decreases in precipitation over the core MLPS genesis region.

“Assuming a fixed radius of influence, the projected reduction in monsoon low-pressure systems would significantly lower the associated precipitation over north-central India,” it said.

Generally poor representation of MLPSs in global climate model simulations erodes the confidence in future projections. To date, only a few studies have investigated the potential changes in south Asian MLPSs, without conclusive findings, it added.