การศึกษาคุณสมบัติเชิงแสงของฝุ่นละอองสำหรับประเทศไทย
Brewer Ozone (O3), Sulfur dioxide (SO2), and the Aerosol Optical Depth (AOD) in a vertical column of the atmosphere were retrieved for the years 1997-2011 at 2 monitoring sites in Thailand (Bangkok and Songkhla). There are similarities between the O3 patterns obtained from the two sites, which are higher in the summer and rainy season compared with winter, although the magnitude of the change in Bangkok is greater than that in Songkhla. SO2 values showed the summer months provide the higher SO2 values in Bangkok, in contrast to Songkhla where the summer months give lower SO2 values. AOD values measured in Bangkok have a distribution that favours the higher values more than Songkhla. In addition, AOD values were higher in the morning and evening hours in Bangkok. In contrast to Songkhla, the AOD values were a slight drop during morning and late afternoon hours. The variation of AOD was seasonal in Bangkok, with the higher values found in summer compared with rainy, whilst there is no clear seasonal pattern of AOD in Songkhla. In addition, Angstrom exponent are parameters described size of the particles and atmospheric turbidity. The size of a particle implies to its impacts in respiratory system. This study has also determined values of AOD in a UV range by Extrapolation of AOD obtained from AERONET at seven wavelengths (675, 500, 440, 380, and 340nm) to estimate AOD at 320nm at nine sites in Thailand. The Linear Method (LM) was used in analysis the as it is a least wavelength dependence in fitting the curve plotted on logarithmic scale of AOD. This study found that aerosol particles show a clear domination by fine mode which is associated with a small particle size in the range of 0.01- 1 . Furthermore, aerosols loading were related to dry weather, forest fires and most importantly, biomass burning. The values were higher in summer due to warmer temperatures and low precipitation. The study results can be linked to health impacts such as respiratory diseases reviewed by Ministry of Public Health that has been increasing.