Study on Aerosol Optical Depth in Winter and Summer Season in Bhaktapur

Niranjan Prasad Sharma, Bal Krishna Sapkota, Binod Bhattarai, Berit Kjeldstad

Abstract

Aerosol optical depth in winter and summer season, 2009 was studied in Bhaktapur (Kausaltar). Spectral aerosol optical depth (AOD) measurements were estimated from a Microtops II Sun Photometer. The results indicated high values in summer and low values in winter. It also showed that AOD is larger in shorter wavelength and gradually decreases towards longer wavelength. The increasing value of AOD in summer season may be due to the accumulation of high speed dust particles. The lower values in winter months are due to the reduction of bigger particles. The spectral dependence of AOD on January 27 was found to be 0.64, 0.52, 0.48 and 0.35. The AOD at 340 nm in January and July were 0.63 and 0.62, respectively. The maximum and minimum value of AOD at 340 nm in the month of April and August were recorded as 1.62 and 0.56, respectively.

Keywords: Sun photometer; Aerosol; Aerosol optical depth; Angstrom parameters; Irradiance

DOI: http://dx.doi.org/10.3126/jie.v8i1-2.5122

Journal of the Institute of Engineering

Vol. 8, No. 1&2, 2010/2011

Page: 269-276

Uploaded Date: 20 July, 2011

Keywords

Sun photometer; Aerosol; Aerosol optical depth; Angstrom parameters; Irradiance
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