An analysis of extensive (scattering, βsca and absorption, βabs coefficients) and intensive (single scattering albedo -SSA, Ångström exponent - α, backscatter fraction - b, and asymmetry parameter - g) properties of aerosols are simultaneously examined for the first time over a source region; urban environment - Ahmedabad, and background site; a high altitude remote location - Gurushikhar over western India revealed significant diurnal, monthly and seasonal variations. βsca and βabs over Ahmedabad are always higher by a factor of 3–5 than Gurushikhar. βsca corrected for variation in relative humidity shows maximum change (>50%) during August, thereby, emphasizing the importance of RH correction on aerosol scattering. SSA is lower over Ahmedabad due to the dominance of absorbing aerosols from the anthropogenic emissions. The annual mean βsca, βabs, SSA, α, and g are found to be 235 ± 128 Mm−1, 64 ± 40 Mm−1, 0.81 ± 0.03, 0.60 ± 0.03 respectively over Ahmedabad, whereas these values are 78 ± 31 Mm−1, 12 ± 6 Mm−1, 0.87 ± 0.04, 1.19 ± 0.31, and 0.61 ± 0.02 respectively over Gurushikhar. A comparison reveals that among the urban regimes Ahmedabad SSA is higher than Delhi, and among the high-altitude locations Gurushikhar SSA is higher than Mukteshwar, and lower than Nainital SSA. The interannual variability in aerosol properties is estimated to be less significant (<10%) over the high altitude region when compared to the source region, thereby, suggesting that the extensive and intensive aerosol properties over the high-altitude remote location can be classified as regional representative background.
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