Characteristics of Black Carbon aerosols over PatialaNorthwestern part ofthe IGP: Source apportionment using cluster and CWT analysis

Özet

The present study represents the variation in characteristics of Black Carbon aerosols over Patiala (Punjab),northwest region of the IGP, India during two separate periods i.e. October 2013–September 2014 and October2015–September 2016. Averaged BC mass concentration were found to be 9.9μgm−3, 6.6μgm−3,3.4μgm−3and 2.8μgm−3during Autumn (Oct–Nov), Winter(Dec–March), Summer(Apr–June) and Monsoon (July–Aug)seasons respectively. During the entire study period, spectral dependence of aerosol mass absorption coefficientreveals that dominant source of BC is biomass burning during autumn season while there is mixed contributionfrom biomass, bio-fuel burning and fossil fuel combustion in rest of the seasons. These results are further sup-ported by seasonal variations in Angstrom coefficient and Delta -C values. Averaged values of mass absorptionefficiency of BC were found to be 3.8 m2g-1, 5.0 m2g-1, 5.6 m2g-1and 7.1 m2g-1during autumn, winter, summerand monsoon seasons respectively. Cluster & Concentration weighted trajectory (CWT) analysis suggests thatpotential sources of BC aerosol over the study region are local as well as transported from distant places mostlysituated in the northwest, south-west and south-east side of the observation site depending upon the meteor-ological conditions and regional anthropogenic activities that varies with season. BC concentration derived fromonline MERRA-2 model for Patiala region and from global inventory EDGARHTAP site for agriculture wasteburning further supports ourfindings.