HR: 09:30h
AN: OS51A-05    [Abstracts]
TI: Deepwater Overflow through Luzon Strait
AU: * Qu, T
EM: tangdong@hawaii.edu
AF: IPRC/SOEST, University of Hawaii, 2525 Correa Road, Honolulu, HI 96822 United States
AU: Girton, J B
EM: girton@apl.washington.edu
AF: Applied Physics Laboratory, University of Washington, 1013 NE 40th Street, Seattle, WA 98105 United States
AU: Whitehead, J A
EM: jwhitehead@whoi.edu
AF: Department of Physical Oceanography, Woods Hole Institution of Oceanography, Woods Hole, MA 02543 United States
AB: This study examines water property distributions in the deep layer of the South China Sea using all available hydrographic data. Our analysis reveals that below about 1500 m there is a persistent baroclinic pressure gradient driving flow from the Pacific into the South China Sea through the Luzon Strait. Applying hydraulic theory with assumptions of zero potential vorticity and flat bottom to the Luzon Strait yields a transport estimate of 2.5 Sv (1 Sv=106 m3 s-1). This result suggests a residence time of only about 30 years in the deep layer of the South China Sea, well below the earlier estimates based on radioactive tracer measurements. Evidence also exists to suggest that topographic control is the correct dynamics of the deepwater overflow. Upon entering the South China Sea via the deep Bashi Channel in the Luzon Strait, water of Pacific origin tends to flow southwestward along local isobaths, and this probably induces a cyclonic circulation in the deep layer of the South China Sea.
DE: 4243 Marginal and semienclosed seas
DE: 4271 Physical and chemical properties of seawater
DE: 4576 Western boundary currents
SC: Ocean Sciences [OS]
MN: 2005 Joint Assembly