Temporal variation of atmospheric aerosols and associated optical and metrologica! Parameters

Abstract

In the present study the particulate matter (PM) mass concentrations such as P M 2 5 and PM1 0 for the winter (November 2016-February 2017) and summer (March 2017-May 2017) months were observed and analyzed. The aerosol optical properties such as MODIS-Aqua AOD (Aerosol optical depth) and Angstrom Exponent (AE) were found the significance seasonal variations. Monthly average AOD (~1.00) and AE>1were observed in the winter season. Whereas, in the summer season monthly average AOD (~0.50) and AE<1were observed. High monthly mean aerosol mass loading was recorded for both P M 2 5 (156.38 ± 21.24 |ig/m3) and PM1 0 (256.54 ± 69.82 |xg/m3) in winter season. Whereas concentrations of P M 2 5 (25.47 ± 16.95 |ig/m3) in April 2017 and PM1 0 (127.68 ± 51.31 |xg/m3) in May 2017 were found low in summer season, typically exceeding national standard. The mean PM2 5/PM1 0 ratio was ~61%> in the winter season, is the indicative of a higher loading of the fine aerosol particles compared to the coarser aerosols in Varanasi. However the unfavorable meteorological conditions are also responsible for the highly increasing atmospheric pollution in Varanasi. © 2019 URSI. All rights reserved.