| Summary: | 碩士 === 國立中央大學 === 遙測科技碩士學位學程 === 99 === Global warming and climate change are the most important issues of the Earth system in the recent years. Atmospheric aerosols can have an important effect on the energy budget of Earth system, and different aerosol type usually exhibits different distinct radiometric characteristic in absorption and scattering. The low absorption leads to top of atmosphere cooling, such as dust, while heating can take place inside the atmosphere for strong absorption, such as smoke. Thus the absorption of aerosol is an important factor of energy balance which can influence in global warming and climate change.
The present study intents to investigate the absorption of smoke plumes from Southeastern Asia bio-mass burning and the dust particles in West Africa by retrieving the single scattering albedo(SSA) from the fusion of satellite data and ground-based data. The concept of retrieving SSA is based on matching the surface reflectivity in multiple view angle retrieved on clear day. The results showed that when the aerosol optical depth is more than 0.5 on hazy day, the error of retrieving SSA can be less than 3%. The mean values of SSA retrievals in the northwestern Thailand are 0.88(blue band), 0.84(red band), 0.84(NIR band) and 0.94 0.91 0.88 in the southeastern Thailand, respectively. According to trajectory analysis, smoke plumes from different region could exhibit distinct optical properties. As for the dust particles, the mean values of retrieved SSA in the western Africa are 0.91, 0.95, and 0.94 in the blue, red, and NIR spectral bands, respectively. However, the SSA values are much lower which may be polluted by the strong absorption of aerosols from ocean, such as sea salt. The results of this study imply that the absorptive property of aerosol mainly relates to the source region of aerosol types and the prevailing wind (monsoon), and the retrievals of absorptive property would be useful to the investigations regarding to the changes of Earth energy budget.
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