Ground-Based and Geospatial Measurement of Aerosol and Black Carbon to Assess the Warming Patterns in a Suburban Location in Himachal Pradesh, India

Retreating glaciers and warming of mountains are some of the serious issues in mountain regions as compared to other regions around the world. In the current study, aerosol optical depth (AOD) and black carbon (BC) were monitored at the ground level using a multiwavelength radiometer (MWR) and Aethalometer AE31, respectively, in the year 2021 and 2022, while satellite data was obtained using MODIS and MEERA-2 which was further analyzed by using a geospatial technique. Furthermore, a fixed box model was used to predict the city-level concentration of BC at the ground level, and source apportionment of pollutants was done using positive matrix factorization (PMF) model. Also, the Hybrid Single-Particle Lagrangian Integrated Trajectory model was run to assess the long-range transportation of aerosol and BC in the region. The results revealed that the mean value of AOD at 500 nm was 0.28 at Mohal, Kullu, Himachal Pradesh, and a higher concentration was observed during summer (0.52 ± 0.07), while black carbon showed the highest concentration of 6657.4 ± 162.74 ngm−3 in winter. A similar trend was observed in the entire Kullu valley using RS-GIS. The fixed box model revealed that the predicted values were close to the measured values with an absolute error of 0.27. Source apportionment of black carbon showed that biomass burning (64.5%) and vehicles (35.4%) are the two contributors of black carbon (BC) in the region. The present study will help researchers to understand the concentration, behavior, and seasonal pattern of aerosols and black carbon in the area, which can be further used to determine the warming pattern in this mountain region.