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Kirti Soni Sachchidanand Singh Tarannum Bano R.S. Tanwar Shambhu Nath B.C. Arya 《Atmospheric environment (Oxford, England : 1994)》2010,44(35):4355-4363
Simultaneous measurements of aerosol absorption and scattering coefficients for the PM2.5 aerosols particles were done at Delhi during April 2008–March 2009 to estimate the aerosol single scattering albedo (SSA) and the Angstrom absorption exponents at the surface. The annual average SSA at 0.55 μm was found to be 0.70 ± 0.07 with only slight variations during the four seasons, summer (0.63 ± 0.06), monsoon (0.69 ± 0.07), winter (0.74 ± 0.03) and spring (0.72 ± 0.04). However, large variations in average absorption and scattering coefficients were seen during these four seasons. The average absorption coefficients during summer, monsoon, winter and spring were found to be 62.47 ± 21.27, 50.95 ± 43.61, 189.65 ± 85.94 and 90.65 ± 33.06 Mm?1 respectively. The corresponding scattering coefficients were 110.46 ± 36.15, 95.34 ± 49.46, 565.59 ± 274.59 and 236.56 ± 96.25 Mm?1. The Angstrom absorption exponent (ασ(abs)) remained close to unity throughout the year averaging at 1.02 ± 0.08, 1.02 ± 0.10, 1.04 ± 0.11, and 1.03 ± 0.05 during summer, monsoon, winter and spring seasons respectively, strongly indicating that the absorption at Delhi aerosol is mainly due to the abundance of black carbon of fossil fuel origin. 相似文献
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Rahul Bhadouria Pratap Srivastava Rishikesh Singh Sachchidanand Tripathi Hema Singh A. S. Raghubanshi 《The Environmentalist》2017,37(1):88-100
The current anthropogenic activities and climate change are increasingly becoming a growing global concern for dry tropical forests. Worldwide, these ecologically important forests have degraded considerably since the past few decades due to such factors. These factors have harmful consequences on the vegetation structure and diversity especially tree seedlings, which may further aggravate climate change. Generally, the vegetation recovery is very slow and unpredictable in the dry tropics due to complex interaction among tree seedling, site (particularly, soil) and climatic conditions. We inculcated that a better understanding of the behavior of individuals of different tree species at seedling stage in dry forests is of immense importance. It is increasingly being recognized for explaining and managing the future composition of plant communities under changing environmental conditions. In this regard, the multi-factorial interaction studies under various resource–disturbance combinations are needed in dry tropical ecosystems to understand the: (1) impact of relative variability in resources and disturbances on the responses of tree seedlings of native species and (2) how the later relates to distinct functional and life history traits of the individual tree species. Most importantly, such studies would improve our limited understanding of how variation (natural and man-made) in nutrient availability, under the influence of other local environmental factors (such as water, light, grass competition, herbivory, fire, allelopathy and enhanced CO2 conditions), would affect the dynamics of dry tropical forest community. It may help in the proper management of these forests. Moreover, it may prove helpful in the current climate change scenario, as change in forest community dynamics may have consequences on soil C sequestration and CO2 efflux at global scale. 相似文献
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Srivastava AK Singh S Tiwari S Bisht DS 《Environmental science and pollution research international》2012,19(4):1144-1158
Introduction
The present work is aimed to understand direct radiation effects due to aerosols over Delhi in the Indo-Gangetic Basin (IGB) region, using detailed chemical analysis of surface measured aerosols during the year 2007. 相似文献4.
Bali Kunal Mishra Amit Kumar Singh Sachchidanand Chandra Subhash Lehahn Yoav 《Environmental science and pollution research international》2019,26(12):11940-11950
Environmental Science and Pollution Research - Dust storms affect the primary productivity of the ocean by providing necessary micronutrients to the surface layer. One such dust storm during March... 相似文献
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