Carbonaceous aerosols and pollutants over Delhi urban environment: Temporal evolution, source apportionment and radiative forcing

Aerosol chemical characterization and role of carbonaceous aerosol on radiative effect over Varanasi in central Indo-Gangetic Plain

“…The errors in the DARE estimates are attributed to errors in AOD and EC concentrations, uncertainties in simulations of SSA, g and to the vertical profiles of aerosol, which were not taken into account for EC estimates. These errors may contribute to an overall uncertainty of~15e20% (Dumka et al, 2013;Bisht et al, 2015). Previous study (Dey and Tripathi, 2008) over Kanpur found that the contribution of anthropogenic aerosols to the ATM ARF was 71%, whereas it was~54% in Delhi , which are comparable in magnitude to the present findings.…”

“…Moreover, the standard tropical atmospheric profiles of pressure, temperature and relative humidity (RH) were used along with daily ozone (267e280 DU) and surface reflectance (0.13e0.20) obtained from Aura Ozone Monitoring Instrument (OMI) version 3 reflectivity data, while the WVC (1.5e3.5 mg m À3 ) was obtained from daily Terra-MODIS observations (level 3, C005.1). On the other hand, the EC radiative effect was estimated via a similar technique by using the SBDART retrievals with and without daily EC concentrations Srivastava et al, 2012;Dumka et al, 2013Dumka et al, , 2014Bisht et al, 2015). In this procedure, the basic input parameters were the AOD, SSA and g. The SSA and g for EC were estimated via OPAC in two steps, (i) including and (ii) excluding the water-soluble and insoluble aerosol components.…”

Molecular characterization of organic aerosols in the Kathmandu Valley, Nepal: insights into primary and secondary sources

“…Their influence 245 and contribution will be discussed in the following sections. The OC/EC ratios found in this study for the Kathmandu valley were similar to other sites in South Asia, like Lumbini (5.16±2.09, 2.41-10.03) (Wan et al, 2017), Delhi (5.86±0.99, 2.9-9.2) (Bisht et al, 2015) and Lahore (3.9 ± 1.6,1.5-7.2) (Alam et al, 2014).…”

Significance of PM2.5 Air Quality at the Indian Capital

“…Moreover, CO dominated during 18% of days in monsoon, and both CO and NO 2 dominated post-monsoon by around 13-14% of days each. Previous studies have indicated that in addition to wet deposition, variation in atmospheric mixing layer heights, air flow pattern can also be a main reason for seasonal differences of pollutant concentrations in this region (Sahu et al, 2009;Bisht et al, 2015). To examine this further, 24-hr back trajectories, originating from the sampling location, were generated using National Oceanic and Atmospheric Administration's Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model.…”