Black carbon emissions and its impact on the monsoon rainfall patterns over the Indian subcontinent: Insights into localized warming effects

Abstract

This study investigates the impact of black carbon (BC) emissions on monsoon rainfall patterns across the Indian subcontinent. The results show that BC exerts localized warming effects, providing valuable insights into the mechanisms influencing the rainfall distribution across the Indian landmass. The study analyzes the vertical profile of mean tropospheric temperature differences between two sets of simulations: (i) with default BC emissions (WBC) and (ii) with BC emissions reduced by 99% (WoBC), conducted for JJAS, 2017, focusing on the region along the eastern coast. The analysis of the tropospheric temperature variations over the eastern coast reveals significant rainfall differences, primarily attributed to the intensification of convective rainfall. The results indicate that WoBC simulation leads to abnormal cooling in the lower troposphere and warming in the mid-upper troposphere, plausibly linked to the release of latent heat from the enhanced convective activity observed over the region. These alterations in the tropospheric temperature profile correspond remarkably well with the changes in the spatial distribution of rainfall over this area, providing valuable insights into the intricate dynamics of the climate system over this region.