Characterization of Black Carbon Aerosols over Darjeeling- A High Altitude

A continuous monitoring of black carbon (BC) aerosols was carried over a high altitude station Darjeeling (27°01′N, 88°15′E; 2200 m asl) at eastern part of Himalaya in India during January 2010–December 2011. In this manuscript we have presented the results of our analysis of the data collected during this interval. This study is focused on the investigation of the temporal variations, potential sources, long-range transport of BC aerosols along with the meteorological impact on these aerosols. BC is found to exhibit strong seasonal variation with the maximum concentration during premonsoon (5.0 ± 1.1 µg/m3) followed by winter (3.9 ± 2.2 µg/m3), postmonsoon (2.9 ± 1.0 µg/m3) and minimum during monsoon (1.7 ± 0.7 µg/m3). BC concentration varies between 0.2–12.8 µg/m3 with an average of 3.4 ± 1.9 µg/m3 over the entire period of study. The diurnal variation of BC aerosol shows sharp morning and evening peaks associated to the local anthropogenic activities as well as the impact of up-slope mountain wind. Amongst the long distant sources, BC concentration associate