The Kuroshio exchange with the South and East China Seas

摘要

The Kuroshio flows along the edges of the marginal East Asian seas such asthe South China Sea (SCS) and East China Sea (ECS). Exchanges of materialsand energy between the Kuroshio and the marginal seas partly control theenvironments of the marginal seas. In particular, saline water from theKuroshio maintains certain salinity in the shelf water in the ECS. Nutrientsfrom the subsurface of the Kuroshio may influence primary production on theshelf. We summarize how the Kuroshio comes into contact with the shelf wateror marginal seas, describing phenomena related to the exchange between theKuroshio and the ECS along with the SCS, using reports in the literaturealong with original data. The Kuroshio tends to intrude into the SCS throughthe Luzon Strait in various manners such as direct intrusion, associatedwith eddies and as a loop current. The Kuroshio intrusion into the shelfregion of the ECS has distinct seasonal variation and the Taiwan WarmCurrent plays a significant role in the determination of water properties inthe outer shelf associated with the Kuroshio intrusion. We then examinephysical processes related to the interaction between the Kuroshio and shelfwater. Interaction between the Kuroshio and the bottom topography is animportant process in the control of the exchange around the shelf break.Vertical mixing and frontal eddies are also important factors that controlthe water exchange and formation of water masses in the outer shelf. Windstress plays a significant role in the exchange with a rather event-likemanner. To determine the source of the water masses, chemical tracers couldbe powerful tools and it is suggested that a significant part of the shelfwater consists of Kuroshio intermediate water.