10th International Aerosol Conference
September 2 - September 7, 2018
America's Center Convention Complex
St. Louis, Missouri, USA

Abstract View


Fingerprinting Pre-monsoon Fine Aerosol Sources over Central Indo-Gangetic Plain

MANISH KUMAR, V.K. Sarma, R.S. Singh, Tirthankar Banerjee, Banaras Hindu University

     Abstract Number: 1448
     Working Group: Source Apportionment

Abstract
Indo-Gangetic Plain (IGP) frequently experiences moderate to severe absorbing aerosols (smoke and dust) especially during pre-monsoon season (March-May), originating mostly from north western arid region. Atmospheric chemistry and potential sources of finer aerosols (PM2.5) were therefore, investigated at an urban location at central IGP during pre-monsoon for three consecutive years (2014-2016). Satellite derived aerosol optical properties i.e. aerosol optical depth (AOD), fine mode fraction (FMF), aerosol vertical profile and Aerosol Index (AI) were studied in synergy with ground observations, to evaluate the role of fine aerosols on columnar aerosol properties. The pre-monsoon aerosol characteristics revealed a substantial fraction of fine aerosols with average PM2.5 concentration of 75 µgm-3 varying from 12-195 µgm-3. The highest concentrations of finer aerosols contributed to 6-80% of the PM10. Terra-MODIS DB AOD ( 0.142-1.309) depict a sharp variability in the influx of both coarse and fine aerosols to the central IGP. Particle size in terms of Angstrom Exponent observed as high as >1.5, indicating co-existence of significant amount of finer aerosols. Further, a clear indication of trans-boundary movement of dust particle was noted using OMI-AI, with variation of aerosol extinction coefficients. Chemical signatures in association with air mass back trajectory further identified the potential sources of aerosols, distributed over north-western arid regions, with mixing of locally emitted finer aerosols. Finally, the source apportionment of pre-monsoon finer aerosol through multivariate and hybrid receptor models highlighted some key sources of aerosol over the region.