Study On The Optical Characteristic Of Phytoplankton And Remote Sensing Inversionin North Yellow Sea

The topic collects the field test data for inherent optical properties in six voyages to North Yellow Sea from March2009to April2010, including absorption coefficient of planktonic algae and concentration of chlorophyll and so on. In the research, it analyzes the absorption coefficient of phytoplankton algae, chlorophyll a concentration, the time and space variation of the absorption coefficient. The thesis discusses the planktonic algae, chlorophyll a concentration, and the remote sensing inversion model of the North Yellow Sea, moreover, it talks about the two-band photographic ratio method and three-band photographic ratio method of the empirical approach is appropriate for this sea.There are following main results:(1) The absorption coefficient of phytoplankton algae in North Yellow Sea has significant timing differences, the absorption peak is675nm and440nm in the spring, which is longer than other three seasons. Meanwhile, there are differences in the absorption coefficient of phytoplankton algae with the changes over time (solar radiation intensity) on the same day, which is mainly caused by the ocean currents.(2) The space distribution about the absorption coefficient of phytoplankton algae in North Yellow Sea are somewhat relative with the spatial distribution of chlorophyll a. This thesis uses the exponential function to fit these two, the fitting results show two main absorption peaks with675nm,440nm band in the absorption spectrum of the planktonic algae, and there are obvious nonlinear trend between the size of absorption coefficient and chlorophyll a concentration. What’s more, the fitting correlation in675nm is higher than in440nm.(3) This thesis uses the exponential function to fit the absorption coefficient of phytoplankton algae and chlorophyll a concentration, and the fitting results show two main absorption peaks with675nm,440nm band in the absorption spectrum of the planktonic algae, and there are obvious nonlinear trend between the size of absorption coefficient and chlorophyll a concentration. What’s more, the fitting correlation in675nm is higher than in440nm.(4) This thesis sets up an inverse model and discusses the model error to the chlorophyll a concentration of the North Yellow Sea through empirical method. The precision about the cubic polynomial of two-band photographic ratio method Rrs(667)/Rrs(443)is higher than the quadratic polynomial of the three-band photographic ratio method(Rrs-1(675)-Rrs-1(695))×Rrs(730). It makes inversion to the chlorophyll a concentration of the northern Yellow Sea. Two-band photographic ratio method is closer to the measured values of the three-band photographic ratio method by the error analysis and discovery of these algorithms.