Poster: Revisiting Nutrient Sources and Budget in the East China Sea

The Kuroshio intrusion has been considered as the major nutrients source of the East China Sea (ECS). With the increasing field measurements in recent years, we revisit the nutrients budget of the ECS by using mass balance calculation. The results reveal that Kuroshio intrusion plays a less important role in nutrients supply to the ECS as compared with the finding from previous studies. For the shelf region shallower than 100 m depth which accounts for 70 – 80% of the total area and at where intensive biological activity occurs, nutrient from the Changjiang and transported via Taiwan Strait exceed the nutrient supply from the Kuroshio intrusion, are the major nutrient sources of the ECS. Most of the Kuroshio water that upwells onto the continental shelf of the ECS flows out of the ECS along a narrow passage between the 100 and 200 m isobaths, and only a small portion of the Kuroshio intrusion with rich nutrient can reach the ECS shelf within 100 m isobath. This study demonstrated that the cross-shore nutrient transport from Kuroshio into the ECS might be overestimated when 200 m isobath was defined as the eastern boundary as widely adopted at present, the transport across the 100 m isobath can better reflects the Kuroshio’s contribution to the nutrient budget of the ECS.