DocumentCode :
1223143
Title :
A high-resolution numerical modeling study of the subtidal circulation in the northern South China Sea
Author :
Chapman, David C. ; Ko, Dong-Shan ; Preller, Ruth H.
Author_Institution :
Phys. Oceanogr. Dept., Woods Hole Oceanogr. Instn., MA, USA
Volume :
29
Issue :
4
fYear :
2004
Firstpage :
1087
Lastpage :
1104
Abstract :
A high-resolution, regional, numerical-model-based, real-time ocean prediction system for the northern South China Sea, called the Northern South China Sea Nowcast/Forecast System (NSCSNFS), has been used to investigate subtidal mesoscale flows during the time period of the Asian Seas International Acoustic Experiment (ASIAEX) field programs. The dynamics are dominated by three influences; 1) surface wind stress, 2) intrusions of the Kuroshio through Luzon Strait, and 3) the large-scale cyclonic gyre that occupies much of the northern South China Sea. Each component primarily drives currents in the upper ocean, so deep currents are rather weak. Wind stress is especially effective at forcing currents over the shallow China shelf. The Kuroshio intrusion tends to flow westward until it meets the northern edge of the large-scale cyclonic gyre. Together, these currents produce an intense, narrow jet directed northwest toward the continental slope, often in the region of the ASIAEX field programs. Upon reaching the slope, the current splits with part flowing northeastward along the slope and part flowing southwestward, producing large horizontal and vertical shears and making this region dynamically very complicated and difficult to simulate. The Kuroshio intrusion tends to be stronger (weaker) when the northeasterly winds are strong (weak) and the large-scale gyre is farther south (north), consistent with conclusions from previous model studies. At the northern boundary, the model produces a persistent northward flow through Taiwan Strait into the East China Sea. Data assimilation in the NSCSNFS model is shown to dampen the system, extracting energy and causing the entire system to spin down.
Keywords :
data assimilation; numerical analysis; oceanographic regions; tides; wind; ASIAEX field program; Asian Seas International Acoustic Experiment; Kuroshio intrusion; NSCSNFS; Northern South China Sea Nowcast/Forecast System; data assimilation; high-resolution numerical modeling; high-resolution regional numerical-model-based real-time ocean prediction system; large-scale cyclonic gyre; northern South China Sea; ocean dynamics; shallow China shelf; subtidal circulation; subtidal mesoscale flow; surface wind stress; Data assimilation; Data mining; Helium; Large-scale systems; Numerical models; Oceans; Real time systems; Sea surface; Stress; Wind forecasting;
fLanguage :
English
Journal_Title :
Oceanic Engineering, IEEE Journal of
Publisher :
ieee
ISSN :
0364-9059
Type :
jour
DOI :
10.1109/JOE.2004.838334
Filename :
1388602
Link To Document :
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