基于分源物理生态耦合模型研究东海表层溶解无机氮对叶绿素季节变化的影响

There are four main external sources of dissolved inorganic nitrogen (DIN) into the East China Sea, including the Kuroshio, Taiwan Strait, river runoff, and atmospheric deposition. In order to explore their combined effects on temporal and spatial variations of phytoplankton in the East China Sea, a physical-biological coupled model and tracking module were used to explore the roles of different sources of DIN in seasonal and spatial variations of surface phytoplankton characterized by chlorophyll a (chl a) and the corresponding relationship between DIN and chl a in the East China Sea. Of the four DIN sources of chl a concentration, the Kuroshio and river runoff are dominant contributors. On the other hand, except for the river runoff, seasonal variation of chl a from other three sources showed a bimodal structure. Different-sourced DIN and the supported chl a displayed distinct seasonal variations and characteristic spatial distribution. chl a supported by different sourced DIN occupied different dominant regions of the East China Sea shelf due to different DIN supplement processes, such as circulation, mixing, stratification, and temperature variations. Studying the effects of nutrients from different sources on phytoplankton in the East China Sea is of great significance for understanding the changes of the East China Sea ecosystem under multiple pressures.