| Research Abstract |
Recent advancement of ocean color remote sensing makes it possible to detect sea surface chlorophyll a concentration. However, in coastal waters, other materials, such as suspended solid (SS) and colored dissolved organic matter (CDOM) interfere chlorophyll determination. In this study, optical data from Omura Bay, Ariake Sound, and East China Sea were collected, and technique to detect phytoplankton and behavior of land origin materials from the optical properties was investigated. Empirical in-water algorithm from sea surface irradiance had error to detect chlorophyll a concentration in the Omura Bay. However, error of satellite chlorophyll a was larger. This implies that atmospheric correction may be larger source of the error than in-water algorithm in this bay. In the Ariake Sound, the behavior of red tide could be detected except in turbid near coastal areas. In the East China Sea, there was a negative correlation between salinity and CDOM, and low salinity water from the Changjiang River may be able detect by ocean color. Furthermore, upwelling of Kuroshio water and bloom of Trichodesmium may be important for the phytoplankton variability in the East China Sea, other than freshwater input. Ocean color remote sensing was also useful in the coastal area of the South Eastern Asia although the interpretation should be careful for turbid water. Neural network inversion algorithm with an optical model with chlorophyll, SS and CDOM was developed, and the verification with field data indicates that future development of satellite algorithm with atmospheric correction scheme was promising.
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