| Summary: | 碩士 === 國立臺灣海洋大學 === 環境生物與漁業科學學系 === 97 === This study compared hydrographic variation in the upwelling area (25~27°N, 121.5~124°E) of NE Taiwan from multi-satellite data, including SST(Sea Surface Temperature), Chl-a(Chlorophyll-a) and SLA(Sea Level Anomaly) before and after typhoon passage. It used AVHRR images to realize distribution of SST inside upwelling area during June to October. Without effect of typhoon, the SST is 26℃~28℃ in June, 27℃~29.25℃ from July to September and 25℃~27.25℃ in October in the upwelling center (122.3°E, 25.5°N). However, after passages of typhoon Lekima, Haitang, Talim and Bilis, mean SST of upwelling region dropped 0.8℃ to 1.73℃, meanwhile, the concentration of chlorophyll-a increased 0.2 mg/m3 to 0.61 mg/m3, and low sea level approximate -200mm to -400mm. In addition, the strong caused by typhoon Haitang, Talim and Bilis lasted 23 to 54 hours according to the instrument records at the Peng-Gia-Yu meteorology station, resulted in significant change in sea surface environment. In other words, the longer strong wind blew by the typhoons, the higher sea surface environment varied. It is suggested that Ekman Pumping might be one of the factors resulting in water mixing and sea surface environment change in NE Taiwan. On the other hand, northwestward wind stress on sea surface may drive the Kuroshio more inshore and enhance intrusion of Kuroshio subsurface water as well as upwelling in NE Taiwan.
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