Investigating the diurnal variations in suspended matter concentration (SPM), chlorophyll-a (Chl-a), and water transparency (TD) holds significant scientific importance in the realm of carbon cycle research in coastal waters, flow field dynamics, and atmospheric correction of second-class water bodies. Presently, the primary data sources employed to study the intraday fluctuations of SPM, Chl-a, and TD in highly dynamic nearshore water bodies encompass ocean model simulation data, buoy observations, and geostationary satellite retrieval products. Ocean numerical models enable a comprehensive examination of the dynamic mechanisms underlying the intraday changes in SPM, Chl-a, and TD in coastal waters. However, accurately simulating these parameters proves challenging due to the complex hydrodynamic conditions prevalent in coastal areas. Buoy observations, while capable of capturing the intraday variations of SPM, Chl-a, and TD at fixed locations with high precision, fail to provide insights into the continuous spatial characteristics of these variables. Geostationary satellite remote sensing, on the other hand, facilitates repeated observations of the Earth within a single day, boasting a high temporal resolution. Consequently, this approach offers a promising avenue for studying the diurnal variation characteristics and patterns of SPM, Chl-a, and TD in highly dynamic nearshore regions.
Drawing upon the existing advancements in intraday monitoring of suspended particulate matter (SPM), chlorophyll-a (Chl-a), and water transparency (TD) in highly dynamic offshore water bodies both domestically and internationally, this study leverages the availability of eight-hourly high-frequency images（08:30-15:30，Beijing time）obtained from the Geostationary Ocean Color Imager (GOCI). These images facilitate effective SPM, Chl-a and TD observation in environments characterized by high turbidity and dynamic water conditions. By capitalizing on the ocean water color elements observed through GOCI, this study enhances the temporal resolution and coverage duration of the observations.
