Future projections of precipitation and temperature extremes at Sohra (Cherrapunji) using Statistical Downscaling Model

Abstract

The Statistical Downscaling Model (SDSM 4.2) is used to project the future precipitation and maximum and minimum temperatures at Sohra, one of the extreme places on earth, using the predictors of the Second-Generation Canadian Earth System Model (CanESM2). The SDSM was calibrated with daily precipitation and temperature data from 1979 to 2005 and validated from 2006 to 2020. Future scenarios generated under the three Representative Concentration Pathways (RCP) 2.6, 4.5 and 8.5 are divided into three future periods, Near Future (2021-2040), Mid Future (2041-2071), and Far Future (2071-2100). It is found that the precipitation and maximum/minimum temperature at Sohra are influenced mainly by the major global predictors; specific humidity at 850 hPa height (s850) and mean temperature at 2 m (temp)/near surface specific humidity (shum), respectively. The downscaled result reveals an increase in Monsoon precipitation in the range of 266-1543 mm under various RCPs compared with the base periods 1985-2005 during the Near Future and 1979-2008 during the Mid and Far Future. Also, annual maximum and minimum temperature increases in the range of 1-2.8 °C and 1.2-3.6 °C for all RCPs in the future.