Wavelength Dependence of Aerosol Optical Depth in 2003 at Sri Samrong District of Sukhothai Province in Thailand

Abstract

The dependence on wavelength of the atmospheric Aerosol Optical Depth (AOD) at Sri Samrongdistrict of Sukhothai province in Thailand were retrieved using multi-filter rotating shadowband radiometer(MFR-7) data at 5 distinct wavelengths of 415, 500, 615, 673 and 870 nm with the consideration of Rayleighscattering and atmospheric column NO₂ and O₃ contents. Diurnal variations of AOD were accurately studiedfor 5-day-period in January and March 2003. Results show that the range of atmospheric column amountsof NO₂ and O₃ are 4-20 DU and 250-370 DU, respectively. The mean Ångström’s parameters of β and αdetermined via least-square fitting method are in the range of 0.097-0.380 and 0.910-1.442, respectively.The obtainable results provide regional information of accurate spectral extinctions in Thailand which canadvantageously provide the aerosol database for radiative forcing study and research in the future.

Keywords : Langley Analysis / Clear Sky / Normalized Diffuse Ratio Variability / ExtinctionRatio / Ångström’s Parameters