Abstract

(JES) are major east Asian marginal seas (EAMS). The complex topography includes the broad shallows of the Sunda Shelf in the south/southwest of SCSi the continental shelf of the Asian landmass in the north, extending from the Gulf of Tonkin to the YES; a deep, elliptical shaped SCS and JES basins, and numerous reef islands and underwater plateaus scattered throughout (Fig. 1a). The shelf that extends from the Gulf of Tonkin to the YES is consistently near 70 m deep, and averages 150 km in width. The EAMS is subjected to a seasonal monsoon system. From April to Au-gust, the weaker southwesterly summer monsoon winds result in a wind stress of just over 0.1 N/m2. From November to March, the stronger northeasterly winter monsoon winds corresponds to a maximum wind stress of nearly 0.3 N /m2. Re-cent observational studies show that the EAMS is energetic and has multi-eddy structure. For example, the SCS synoptic eddy structure was identified in May 1995 using the airborne expendable bathythermograph (AXBT) data (Chu et al., 1998a), the eddy spatiotemporal scales in the YES were identified using the Navy's Master Oceanographic Observational Data Set (MOODS) during 1929-1991 (Chu et al., 1997a,b), and the seasonal JES multi-eddy structure from a