Comparative Analysis of Aerosol Optical Properties over High Altitude Region of Western Ghats in Southern India

Abstract

Observations of aerosols and Black Carbon (BC) were carried out at Ooty, high altitude region in Western Ghats using Multi wavelength solar radiometer (MWR) and Aethalometer. For the years 2018 and 2021, the Optical Characteristics of Aerosols and Clouds (OPAC) model was used to estimate monthly, seasonal, and spectral variations of aerosol optical properties such as Aerosol Optical Depth (AOD), Single Scattering Albedo (SSA), and Asymmetry Parameter (ASY). The dominance of fine anthropogenic aerosols was shown by higher AOD during the pre-monsoon period. The maximum and minimum seasonal variation of AOD occurred during pre-monsoon (1.1 ± 0.02) and winter (0.21 ± 0.001) respectively. The significant spectral variation of AOD occurred during March to May as it decreases with the increase in wavelength .The SSA increases as the wavelength increases, ranged between 0.83 ± 0.02 and 0.77 ± 0.01.The variability of SSA is significant during January and February which is a characteristic of coarse type aerosols. Asymmetry Parameter with the monthly mean of 0.75 ± 0.01 indicated the forward scattering of aerosols and there is no significant difference in them over the years.