Research On Water Color Optical Properties And Retrieval Algorithms Of Pigment Concentrations Around Hong Kong And Its Vicinity

Hong Kong sea area is round about 1,800 sq. km, where the sea waters greatly relate to human entertainment, aquiculture, industries, shipping and so on. The water constituents are quite complicated in Hong Kong sea area. The eastern area, where chlorophyll concentrations are relatively higher, is a high-frequency red tides area. The western area belongs to estuarial entironment, which is the main let way of the Pearl River. For the purpose of understanding the water quality and entironment of Hong Kong sea area, developing and utilizing the coastal zone, it is necessary to understand the water quality, establish suitable optical algorithms of this area. With an expectancy to make some contributions on water color research, the main research of this dissertation is focusing on water optical property analysis and retrieval algorithms.Based on the in-situ data collected around Hong Kong and its vicinity from March to May in 2001, the water constituents absorption spectra characteristics are analyzed, which mainly concentrates on the relationships among TSM, chlorophyll-a concentrations and the absorption coefficients of total suspended particles, phytoplankton pigment and de-pigment particles. The empirical mode between and phytoplankton pigment absorption coefficients are developed with a well correlation. The empirical slopes of CDOM and de-pigment absorption spectra are simulated, which are suitable to the sea areas.Profile data are used to extrapolate the under water remote sensing reflectance rrs. Moreover, based on the absorption and backscattering models of IOPs, a model for simulating rrs has been completed. Compared with the extrapolated data of rrs, the simulated spectra are similar in graph but lower in values.Semi-analytical algorithm is used to retrieve , and the relative errors are mostly below 45% compared with in-situ measurements. Based on the quasi-analytical algorithm developed by Lee, total absorption coefficients of water components have been retrieved, but with a higher discrepancy because of unsuitable scattering models. Finally the application of two empirical algorithms, OC2 and OC4, are tested in this sea area as well, whose results are plain. Overall, more in-situ data from different time and stations are necessary to establish more suitable retrieve models of this sea area.