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題名 | 結合MODIS與MISR觀測資料在氣膠單次散射反照率反演之應用=Fusion of MODIS-MISR Data to Estimate Single Scattering Albedo for Different Aerosol Type |
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作者姓名(中文) | 李國揚; 連偉宏; 張國恩; 林唐煌; | 書刊名 | 航測及遙測學刊 |
卷期 | 17:3 2013.11[民102.11] |
頁次 | 頁203-220 |
分類號 | 328.2 |
關鍵詞 | 單次散射反照率; 氣膠光學厚度; MODIS; MISR; AERONET; Single scattering albedo; SSA; Aerosol optical depth; AOD; |
語文 | 中文(Chinese) |
中文摘要 | 本研究主要目的是結合衛星資料與地面觀測資料反演單次散射反照率,並針對東南亞生質燃燒產生的煙塵與西非地區的沙塵探討不同氣膠種類的吸收及散射特性。主要的概念是使用一組同一地區時間相近的衛星影像,以乾淨大氣的地表反射特性作為參考基準,來反演受氣膠影響事件的單次散射反照率。研究結果顯示,當受氣膠影響事件的氣膠光學厚度高於0.5時,單次散射反照率反演的誤差可在3%以內,其中由生質燃燒產生的煙塵(泰國西北邊)單次散射反照率分別為0.88(藍光頻道)、0.84(紅光頻道)、0.84(近紅外光頻道),吸收特性相當明顯,而在泰國東南邊的單次散射反照率為0.94、0.91、0.88,吸收特性相對較弱,透過氣流軌跡的分析顯示,吸收特性之強弱主要與氣膠的來源地區有關。而非洲西部地區沙塵反演各頻道的單次散射反照率則分別為0.91、0.95、0.94,相對於生質燃燒具有較強的散射特性,但在夏季期間則具有較低值,由於該季節北風盛行,推估可能受到來自海洋地區吸收較強氣膠的影響,如海鹽等。整體研究結果顯示,不同地區氣膠吸收及散射特性可具有明顯的差異,主要與氣膠源區和盛行季風有關,而準確地計算氣膠吸收/散射的特性對於地球能量收支相關研究將有很大的助益。 |
英文摘要 | 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 AERONET 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 in summer 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. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。