Assessment of carbonaceous fractions in ambient aerosols at high altitude and lowland urban locations of Kumaon Province, Indian Himalaya

Abstract The present study investigates the characteristics of carbonaceous species like organic carbon (OC) and elemental (EC) in ambient total suspended particulates (TSP) at Bhimtal (high altitude urban, 1413 m asl) Pantnagar (lowland 224 sites Kumaon province Uttarakhand, Indian Himalayan region during winter summer 2017–2018. Ambient TSP samples were taken on quartz filters with high volume sampler followed by OC EC quantification using IMPROVE_thermal optical reflectance protocol. Results showed that distinct seasonal differences levels observed both sites, while day- night-time concentrations did not show notable variations. Further, aerosols (TCA) approximately 3.0 1.3 times higher than for summer, respectively, where estimated TCA accounted ~ 30% to sites. Among quantified eight fractions, OC2 OC3 EC1 EC2 most abundant components. char-EC soot-EC a similar pattern char contributed significantly as 89–90% OC/EC ratios suggested formation secondary char-EC/soot-EC implied biomass burning major sources aerosols. Pearson correlation analysis indicated significant correlations which infers different mechanisms soot. Most parameters exhibited contrasting positive negative boundary layer height, temperature, solar radiation Pantnagar, respectively.