Four-year Spatiotemporal Distribution & Analysis of PM2.5and its Precursor Air Pollutant SO2, NO2& NH3and their Impact on LST in Bengaluru City, India

Abstract

Bengaluru is one of the most populated cities in India. The rise in urbanization has caused an increase in air pollutant concentrations and land surface temperature. The present study explored the four-year (2019-2022) seasonal relationship between PM2.5 and its precursor's air pollutants SO2, NO2, NH3, and meteorological parameters (WS, WD, RH, SR). Another relationship was explored to find the combined impact of air pollutants (PM2.5 SO2, NO2, NH3) and meteorological parameters on LST. Results from correlation analysis show that PM2.5 is strongly and very strongly correlated with NH3 during 2022 and moderately correlated with SO2 in 2021 and NO2 in 2022, respectively, during both seasons. LST is positively associated with air pollutants except for PM2.5 in 2020 and NO2 in 2022. The multiple linear regression analysis shows that PM2.5 strongly correlates with its precursors and meteorological parameter in both summers (0.66 to 0.74) and winters (0.59 to 0.93). Similarly, LST is strongly associated with all four air pollutants and meteorological parameters in summer (0.66 to 0.81) and winter from 0.60 to 0.79 from 2019 to 2021. The result shows that multiple parameters are responsible for the formation of secondary PM2.5 and change in LST.