Variability of Optical Properties for Atmospheric Aerosol in Kuching City Using AERONET Sunphotometer

The knowledge of aerosol optical properties is important for estimation of radiative balance effect to the Earth's system. Aerosol can have directly effect to the radiation by scattering and absorption process depending on their chemical and physical properties. Uncertainties in estimation of radiative effect are cause by lack of knowledge for aerosol properties. AERONET Sun photometer had been used to measure the AOD, linear regressions to calculate Angstrom exponent and inversion algorithm to retrieve single scattering albedo and refractive index over Kuching, Sarawak from August 2011 until October 2011. The mean values of AOD for August was (0.4014+/-0.3126), for September was reported as (0.3158+/-0.1877) and (0.1689+/-0.0813) for October 2011. The minimum value for Angstrom is 0.3233 and the maximum value is 1.9325 which indicates a presence of fine mode aerosol and coarse mode aerosol. The averaged SSA for August at 440nm was 0.8997 and 0.7604 for 1020nm meanwhile for September SSA value was 0.9586 for 440nm and 0.9239 for 1020nm. It shows an increasing of urban pollution and biomass burning aerosol. The refractive index for real part and imaginary part measurement suggest that absorbing aerosols are more dominant in Kuching, Sarawak.