East Asian Marginal Seas Prediction using a Coastal Atmosphere-Ocean Coupled System (CAOCS)

A coastal atmosphere-ocean coupled system (CAOCS) is developed with Princeton Ocean Model (POM) as the oceanic component, and with National Center for Atmospheric Research (NCAR) regional model (MM5) as the atmospheric component. The surface fluxes of water, heat (excluding solar radiation), and momentum are applied synchronously with opposite signs in the atmosphere and ocean. Flux adjustments are not used. The CAOCS is portable and easy to implemented into any regional area. In this paper we show the capability of CAOCS for the South China Sea data assimilation and air-ocean prediction. The South China Sea (SCS) is a semi-enclosed tropical sea located between the Asian land mass to the north and west, the Philippine Islands to the east, Borneo to the southeast, and Indonesia to the south. It includes the shallow Gulf of Thailand and connections to the East China Sea (through Taiwan Strait), the Pacific Ocean (through the Luzon Strait), the Sulu Sea, the Java Sea (through the Gasper and Karimata Straits) and to the Indian Ocean (through the Strait of Malacca). All of these straits are shallow except the Luzon Strait whose maximum depth is 1800 m. Understanding the mechanisms of monsoon onset improves the intraseasonal and interannual prediction. An international South China Sea Monsoon Experiment (SCSMEX) was recently conducted to provide a better understanding of the key physical processes for the onset, maintenance and variability of the monsoon over Southeast Asia and southern China leading to improved prediction (SCSMEX Science Plan, 1995). As one of the SCSMEX modeling efforts, the CAOCS was used and validated for the SCSMEX data assimilation and prediction.

References

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Chu, P.C., S.H. Lu, and W.T. Liu, "Uncertainty of the South China Sea prediction using NSCAT and NCEP winds during tropical storm Ernie 1996," Journal of Geophysical Research, 104, 11273-11289, 1999.

Chu, P.C., S.H. Lu, and Y.C. Chen, A coastal atmosphere-ocean coupled system (CAOCS) evaluated by an airborne expandable bathythermograph survey in the South China Sea, May 1995. Journal of Oceanography, 55, 543-558, 1999.

Chu, P.C., N.L. Edmons, and C.W. Fan, "Dynamical mechanisms for the South China Sea seasonal circulation and thermohaline variabilities." Journal of Physical Oceanography, 29, 2971-2989, 1999.