Browsing by Author "Atinderpal Singh"

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Characterization and radiative impact of dust aerosols over northwestern part of India: a case study during a severe dust storm
(Springer-Verlag Wien, 2016) Atinderpal Singh; Shani Tiwari; Deepti Sharma; Darshan Singh; Suresh Tiwari; Atul Kumar Srivastava; Neeraj Rastogi; A.K. Singh
The present study focused on examining the impact of a severe dust storm (DS) on aerosol properties over Patiala (30.33°N, 76.4°E), a site located in the northwestern part of India during 20th–23rd March, 2012. On 20th March, average PM10 mass concentration increased abruptly from 182 to 817 µg m−3 along with significant increase in the number density of coarser particles (diameter >0.45 µm). During DS, spectral aerosol optical depth (AOD) increases significantly with more increase at longer wavelengths resulting in weak wavelength dependence (AOD at 380 nm increases by ~210 % and at 870 nm by ~270 % on 20th March). Significant decrease in Ångström exponent (AE; α380–870) from 0.56 to 0.11 and fine-mode fraction (FMF; PM2.5/PM10) from 0.49 to 0.25 indicates dominance of coarser particles over the station. Net short wave (SW) radiation flux has been decreased by ~20 % and single scattering albedo (SSA675) has been increased from 0.86 (19th March) to 0.90 (20th March). This observation is attributed to additional loading of scattering type aerosols on arrival of DS. Wavelength dependence of SSA reverses during DS and it increases with wavelength due to dominance of coarse-mode particles. Atmospheric aerosol radiative forcing (ATM ARF) during DS ranged from +45 to +77 W m−2, consequently heating the lower atmosphere up to 2.2 K day−1. Significant atmospheric heating rate due to severe dust storm may affect the regional atmospheric dynamics and hence the climate system. © 2016, Springer-Verlag Wien.
Editorial: The Role of Climate and Air Pollution in Human Health and Urban Chemistry in Asian Cities
(Frontiers Media S.A., 2022) Prashant Rajput; Atinderpal Singh; Jai Prakash; Manish Kumar
[No abstract available]
Effects of crop residue burning on aerosol properties, plume characteristics, and long-range transport over northern India
(Wiley-Blackwell, 2014) D.G. Kaskaoutis; S. Kumar; D. Sharma; R.P. Singh; S.K. Kharol; M. Sharma; A.K. Singh; S. Singh; Atinderpal Singh; D. Singh
Aerosol emissions from biomass burning are of specific interest over the globe due to their strong radiative impacts and climate implications. The present study examines the impact of paddy crop residue burning over northern India during the postmonsoon (October-November) season of 2012 on modification of aerosol properties, as well as the long-range transport of smoke plumes, altitude characteristics, and affected areas via the synergy of ground-based measurements and satellite observations. During this period, Moderate Resolution Imaging Spectroradiometer (MODIS) images show a thick smoke/hazy aerosol layer below 2-2.5 km in the atmosphere covering nearly the whole Indo-Gangetic Plains (IGP). The air mass trajectories originating from the biomass-burning source region over Punjab at 500m reveal a potential aerosol transport pathway along the Ganges valley from west to east, resulting in a strong aerosol optical depth (AOD) gradient. Sometimes, depending upon the wind direction and meteorological conditions, the plumes also influence central India, the Arabian Sea, and the Bay of Bengal, thus contributing to Asian pollution outflow. The increased number of fire counts (Terra and Aqua MODIS data) is associated with severe aerosol-laden atmospheres (AOD500 nm>1.0) over six IGP locations, high values of Ångström exponent (>1.2), high particulate mass 2.5 (PM2.5) concentrations (>100-150 µgm-3), and enhanced Ozone Monitoring Instrument Aerosol Index gradient (~2.5) and NO2 concentrations (~6 × 1015mol/cm2), indicating the dominance of smoke aerosols from agricultural crop residue burning. The aerosol size distribution is shifted toward the fine-mode fraction, also exhibiting an increase in the radius of fine aerosols due to coagulation processes in a highly turbid environment. The spectral variation of the single-scattering albedo reveals enhanced dominance of moderately absorbing aerosols, while the aerosol properties, modification, and mixing atmospheric processes differentiate along the IGP sites depending on the distance from the aerosol source, urban influence, and local characteristics. © 2014. American Geophysical Union. All Rights Reserved.