Volume 14, No. 3, April 2014, Pages 608-622 PDF(944 KB)
Seasonal Variability of Atmospheric Aerosol Parameters over Greater Noida Using Ground Sunphotometer Observations
Manish Sharma1, Dimitris G. Kaskaoutis2, Ramesh P. Singh3, Sachchidanand Singh4
1 Research and Technology Development Centre (RTDC), Sharda University, Greater Noida-NCR, 203201, India
2 Department of Physics, School of Natural Sciences, Shiv Nadar University, Dadri-NCR, 203207, India
3 School of Earth and Environmental Sciences, Schmid College of Science and Technology, Chapman University, One University Drive, Orange, CA 92866, USA
4 Radio & Atmospheric Sciences Division, CSIR-National Physical Laboratory, New Delhi - 110012, India
Atmospheric aerosols over northern India are subject of significant temporal and spatial variability and many studies have been carried out to investigate their physico-chemical and optical properties. The present work emphasizes on examining the aerosol optical properties and types over Greater Noida, Delhi region, using ground-based sun photometer data during the period 2010–2012. The analysis reveals a relatively high mean aerosol optical depth at 500 nm (AOD500 = 0.82 ± 0.39), associated with a moderate Angstrom exponent α440–870 of 0.95 ± 0.37. Both parameters, exhibit significant daily, monthly and seasonal variability with higher values of AOD500 during post-monsoon (0.98 ± 0.50) and winter (0.87 ± 0.35) seasons associated with high α values (> 1.1) suggesting significant urban and biomass-burning contribution. On monthly basis, the highest AOD is found during July and November and the lowest one in the transition months of March and September. The aerosol-type discrimination via the relationship AOD vs. α shows a clear dominance of urban/industrial and biomass-burning aerosols during post-monsoon and winter in fractions of 74.5% and 72%, respectively, while aerosols of desert-dust characteristics were most frequent in pre-monsoon (41.7%) and monsoon (21%) seasons. In general, the analysis shows a rather well-mixed aerosol type under very turbid atmosphere, which is associated with the long range transport of pollutants through the westerly winds from the Thar desert and biomass burning in the western parts of India.
Atmospheric aerosols; Sunphotometer; Aerosol optical depth; Dust storm; AERONET; Dust; Biomass burning.