Wind stress over the Pacific Ocean east of Japan drives the shelf circulation east of China

Abstract

In the western Pacific Ocean, the Kuroshio cross-shelf intrusion and the shelf circulation are vital components of the coastal environment. However, the key dynamic factors driving them remained unclear. Our model and theoretical analysis show that wind stress over the open Pacific Ocean east of Japan drives a net equatorward water flux of 2.2 Sv, and this flux sets up a south-north sea surface drop from the East China Sea (ECS) to the Japan Sea which drives a throughflow of 2.6 Sv poleward through the Tsushima Strait. This throughflow requires a shelf circulation in the ECS to balance the mass flux. Thus, the Kuroshio Current must intrude onto the ECS shelf and there must be a poleward flowing Taiwan Warm Current through Taiwan Strait. It is the wind stress over the Northeastern Pacific Ocean interior rather than the local wind that drives and regulate both the Kuroshio cross-shelf intrusion and the shelf circulation.