中国东部海表层悬浮物浓度长期变化规律研究OA

Marine suspended particulate matter(SPM)is a critical environmental factor in the ocean.Its concentration variations significantly impact marine geomorphology,ecosystems,and biogeochemical cycles.The China's eastern sea,as a typical marginal sea,features a complex hydrodynamic environ-ment.It is not only significantly influenced by human activities but also highly sensitive to climate change.Against the backdrop of intensifying global climate change and increasing human activities,the marine environment of the ECSs is undergoing significant transformations,leading to complex spatio-temporal variations in surface SPM concentration.However,existing studies are often limited to short time scales or localized areas,and lack a systematic understanding of the long-term evolution in surface SPM concentration under the combined influence of multiple environmental factors.To address this,this study uses MODIS satellite remote sensing data to derive surface SPM concentration in the ECSs from 2003 to 2023,and employs the Data Interpolating Empirical Orthogonal Functions(DINEOF)method to reconstruct missing data.The surface SPM concentration in the ECSs shows an overall decli-ning trend,with both the area and mean concentration of high-concentration regions decreasing from 2003 to 2023.In coastal areas,the surface SPM concentration significantly declines in the three major bays of the Bohai Sea,the Subei Shoal,the Yangtze River Estuary,and Hangzhou Bay,while increases were noted along the southwestern coast of the Shandong Peninsula and the Zhejiang-Fujian coast.Off-shore regions maintain relatively low surface SPM concentration without notable long-term changes.Wind speed changes are the dominant driver of long-term trends in surface SPM concentration in coastal areas,where regions with significant decrease(or increase)in wind speed leading to corresponding de-cline(or rise)in surface SPM concentration.In contrast,the influence of sediment discharge from the Yellow River and the Yangtze River on surface SPM concentration is limited to their respective estuar-ies.