长江口及邻近海域的浊度日变化遥感研究

Study on Diurnal Variation of Turbidity in the Yangtze Estuary and Adjacent Areas by Remote Sensing

基于长江口及东海的浮标观测资料,建立针对静止海洋光学传感器(GOCI)的瑞利校正反射率数据的浊度反演模型,并对长江口及邻近海域的浊度进行遥感反演。研究结果显示:680 nm波段对浊度信号最敏感,基于多波段组合建立的模型的反演效果最佳;长江口及邻近海域的浊度分布呈现出近岸高、远岸低的特征,长江口到杭州湾的浊度一天内呈先增后减的变化趋势,杭州湾以南的日变化趋势则相反;水体浊度日变化受海洋动力的影响可通过浑浊带表征,浑浊带外的水体浊度日变化不显著;浑浊带具有显著的季节性特征,呈现出冬远夏近的趋势,与海流有关。

In this study, we established a turbidity inversion model for the Rayleigh-corrected reflectance data from the geostationary ocean color imager(GOCI) based on the buoy observation data obtained from the Yangtze estuary and the East China sea. In addition, remote sensing was used to retrieve the turbidity of the Yangtze estuary and the adjacent sea areas. This research results show that the 680 nm band is the most sensitive to turbidity signals and that the inversion effect can be optimally established by model combining multiple bands. The turbidity distributions in the Yangtze estuary and the adjacent sea areas are observed to be high near the shore and low away from the shore. Further, the turbidity initially increases and subsequently decreases from the Yangtze estuary to the Hangzhou bay, and the changing trend is reversed toward the south of the Hangzhou bay within a day. The diurnal variation of the turbidity of water body, which is affected by the ocean dynamics, can be characterized based on the turbidity zone, and the turbidity of the water outside the turbidity zone does not change significantly within days. The turbidity zone exhibits significant seasonal characteristics, showing a tendency of farther in winter and nearer in summer, which is related to ocean currents.