Responses of the South China Sea to Mesoscale Disturbances from the Pacific

Abstract

The South China Sea (SCS) connects the western North Pacific (WNP) through the Luzon Strait (LS), which faces the high-energy band of mesoscale disturbances such as the Rossby waves (RWs) and eddies with a horizontal length scale of O (100–500 km) originating from the Pacific. This chapter reviews recent progress in the research of the interaction of RWs and eddies with the western boundary and current, their penetration into the SCS and response of the SCS to disturbances from the Pacific. Cruise and satellite observations indicate that the westward-propagating RWs and eddies may strongly interact with the western boundary and the Kuroshio as they approach the western boundary region. In favorable cases, there is a high possibility for them to enter the SCS through the LS. The results of theoretical analysis and satellite altimeter sea level time series data analysis indicate that disturbances of the RWs and eddies in the SCS may have resonance with the intrinsic Rossby normal modes and standing wave modes in the SCS deep basin. This coupling processes of the momentum and the energy contribute to sustaining of the grouped mesoscale eddies and intraseasonal variabilities of the circulation in the SCS.