Mooring Observations and Numerical Modeling of Thermal Structures in the South China Sea
Abstract
Three sets of Autonomous Temperature Line Acquisition Systems were deployed in the South China Sea. Gaps aside, the data covered nearly 3 years at the northern station and about 2 years farther south. Fluctuations ranged from episodic to interannual. Internal tides, more diurnal than semidiurnal, were active basinwide. Twelve typhoons passed during measurement periods. The most severe one, typhoon Babs in 1998, caused a temperature drop of over 7 C at 50 m. Despite strong monsoons, only near-surface temperature showed clear seasonal variations. Intraseasonal variations induced by mesoscale eddy stood out much better at subsurface depths. Propagating eddies aside, some eddies were seasonal and nearly stationary. From daily archives of an eddy-resolving, data-assimilating ocean model (East Asian Seas Nowcast/Forecast System), we identified two paradigms leading to the generation of a persistent spring-summer warm eddy in the central-western basin. In normal years, a complete cyclonic gyre was driven by a strong winter northeast monsoon. Transition from SW to NE monsoon also often led to a warm eddy generation in southern latitudes, when the summer eastward jet departing from central Vietnam broke up.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2010
- Accession Number
- ADA536915
Entities
People
- Dong S. Ko
- Michael J. McPhaden
- Ming-Huei Chang
- Shenn-yu Chao
- Tswen Y. Tang
- Wen-der Liang
- Ya-Ting Chang
- Yiing J. Yang
Organizations
- United States Naval Research Laboratory