Variation in black carbon mass concentration over an urban site in the eastern coastal plains of the Indian sub-continent

Abstract

Black carbon (BC) mass concentration variation has been studied, over a period of 2 years (June 2010–May 2012) at Bhubaneswar. Daily, monthly and seasonal measurements revealed a clear winter maxima (5.6 μg/m3) of BC followed by post-monsoon (4.05 μg/m3), monsoon (3.02 μg/m3) and pre-monsoon (2.46 μg/m3). Nighttime BC mass concentrations have been found to be distinctly higher during winter followed by post-monsoon and monsoon. Investigations reveal that the winter maxima are due to a stable atmospheric condition and long-range transport over the Indo-Gangetic Plain and Western Asia. Local boundary layer dynamics and anthropogenic activities have been assumed to have a pronounced effect on the diurnal cycle seasonally. Statistical analysis suggests significant variation of BC during the months and non-significant during the days. The study also gives an insight into importance of BC study from health angle and suggests an assessment and management framework. Source apportionment study suggests that BC mass concentration observed at Bhubaneswar is generally dominated by fossil fuel combustion.