Optical and Radiative Properties of Aerosols over Two Locations in the North-West Part of India during Premonsoon Season

Abstract

The present study examines the aerosol characteristics over two locations in the northwest region of India (Dehradun and Patiala) during premonsoon season of 2013. The average mass concentrations of particulates (PM10; PM2.5; PM1) were found to be118±36,34±11, and19±10 µgm−3and140±48,30±13, and14±06 µgm−3over Dehradun and Patiala, respectively. The average aerosol optical depth (AOD500 nm) is observed to be0.62±0.11over Dehradun and0.56±0.21over Patiala. Ångström exponent and fine mode fraction show higher values over Dehradun as compared to Patiala. The average mass concentration of black carbon was found to be3343±546 ngm−3and6335±760 ngm−3over Dehradun and Patiala, respectively. The diurnal pattern of BC is mainly controlled by boundary layer dynamics and local anthropogenic activities over both the stations. The average single scattering albedo (SSA500 nm) exhibited low value over Patiala (0.83±0.01) in comparison to Dehradun (0.90±0.01), suggesting the abundance of absorbing type aerosols over Patiala. The average atmospheric aerosol radiative forcing is +37.34 Wm−2and +54.81 Wm−2over Dehradun and Patiala, respectively, leading to atmospheric heating rate of 1.0 K day−1over Dehradun and 1.5 K day−1over Patiala.

Long-Term Variability of Modis 3 km Aerosol Optical Depth Over Indian Region

“…Several field campaigns have already been undertaken in the Asian region to study the aerosol properties and its impacts on the continent and the surrounding ocean regions like Indian Ocean Experiment (INDOEX), the Arabian Sea Monsoon Experiment (ARMEX), the Bay of Bengal Monsoon Experiment (BOBMEX), the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB) and the overview of these results are reported elsewhere (Ramanathan et al 2001;Mandal et al 2006;Moorthy et al 2008). There have been numerous studies done on aerosol properties over north Indian region, particularly Indo Gangetic Plain (IGP) (Kaskaoutis et al 2013;Srivastava et al 2014;Kant et al 2015). All of these studies have significantly improved our understanding of aerosol optical and microphysical properties and their variability across the Indian subcontinent.…”

Variability of aerosol optical depth and aerosol radiative forcing over Northwest Himalayan region

“…Single Scattering Albedo (SSA) and Asymmetry parameter (g) were obtained using OPAC model developed by Hess [27] synchronous with the ground observations. In present study, we adapted semi urban pollutant model appropriated to the geographical location and air mass back trajectories [28]. The aerosol types considered for the study location are soot, water soluble, insoluble, mineral accumulation, and mineral transport.…”

“…The single scattering albedo (SSA) and asymmetry parameter (g) were simulated with the help of Optical Properties of Aerosol and Clouds (OPAC) model. [10] and during autumn season, the atmosphere is loaded with black carbon and other fine mode organic particles due to large-scale biomass burning from the Indo-Gangetic plain (IGP) [11]. During the year 2015, the annual rainfall the annual mean temperature over the region are around 1565 mm and s 21.7 C respectively while the average Relative Humidity was observed 70% and the wind is normally north-westerly with speed of less than 3(km/h)(figure1).…”