Variations in black carbon aerosol, carbon monoxide and ozone over an urban area of Hyderabad, India, during the forest fire season

Urban air quality monitoring plays an important role due to high concentration of particle sources and a large population exposed to elevated particle concentrations. Continuous ground based measurements of black carbon (BC) aerosol; carbon monoxide (CO) and ozone (O3) were carried out in the tropical urban region of Hyderabad, India, during the forest fire season. Julian day variation of BC, CO and ozone showed high values on certain days. In order to ascertain the additional sources for observed high concentration of BC and CO, DMSP-OLS nighttime satellite data over the Indian region were processed for occurrence of forest fires. Results of the analysis suggested a higher incidence of forest fires on days with higher concentrations of BC and CO and a spatial distribution of forest fires; wind trajectories were observed to have a bearing on the higher values of BC, CO and ozone. Results are discussed in the paper.