Showing papers by "Quanan Zheng published in 2005"

A Note on the South China Sea Shallow Interocean Circulation

Abstract: The existing estimates of the volume transport from the Pacific Ocean to the South China Sea are summarized, showing an annual mean westward transport, with the Taiwan Strait outflow subtracted, of 3.5±2.0 Sv (1 Sv=106 m3 s−1). Results of a global ocean circulation model show an annual mean transport of 3.9 Sv from the Pacific to the Indian Ocean through the South China Sea. The boreal winter transport is larger and exhibits a South China Sea branch of the Pacific-to-Indian Ocean throughflow, which originates from the western Philippine Sea toward the Indonesian Seas through the South China Sea, as well as through the Karimata and Mindoro Straits. The southwestward current near the continental slope of the northern South China Sea is shown to be a combination of this branch and the interior circulation gyre. This winter branch can be confirmed by trajectories of satellite-tracked drifters, which clearly show a flow from the Luzon Strait to the Karimata Strait in winter. In summer, the flow in the Karimata Strait is reversed. Numerical model results indicate that the Pacific water can enter the South China Sea and exit toward the Sulu Sea, but no observational evidence is available. The roles of the throughflow branch in the circulation, water properties and air-sea exchange of the South China Sea, and in enhancing and regulating the volume transport and reducing the heat transport of the Indonesian Throughflow, are discussed.

Cruise observations of a cold core ring and β - spiral on the East China Sea continental shelf

Abstract: [1] Cruise observations with CTDs (Conductivity-Temperature-Depth profiler) and a moored ADCP (Acoustic Doppler Current Profiler) were carried out on the continental shelf of southern East China Sea (ECS) in summer 2003. Analyses of the cruise data reveal a low temperature belt sandwiched by warm waters on the shallow water side and on the continental slope side. Within the belt there are three cold centers with horizontal scales of 30 to 100 km distributed as a chain from the southwest to the northeast. The upward protruding isotherms and β – spiral-like daily averaged horizontal velocity structure indicate that the northeast cold center has all features of a mesoscale cold core ring. Estimated vertical velocity is of the order of 5 × 10−5 m s−1.