Fig. 1

Spatial distribution of the mean eddy kinetic energy in the South China Sea based on the daily AVISO SLA data of winters (Dec., Jan., Feb.) from 2005 to 2015. Topography is shown by the gray isobaths at 200, and 1500 m, respectively"

Fig. 2

Topography of the South China Sea used in the first nested model domain. Gray isobaths show the depth at 200, and 1500 m, respectively. The online second nested domain is delineated by the black box"

Fig. 3

Spatial distribution of the Rossby number with horizontal velocity (vector) at 5-m depth in the northern South of China Sea. Topography is shown by the black isobaths at 200 and 1500 m, respectively. The black box denotes the eddy region"

Fig. 4

Horizontal distribution of potential density with horizontal velocity (vector) at 5-m depth in the mesoscale eddy. Topography is shown by the black thick isobaths at 200 and 1500 m, respectively. The black box denotes the front region"

Fig. 5

Spatial structure of Okubo-Weiss parameter (a) and frontal sharpness (b) at 5-m depth in the front. Topography is shown by the black isobath at 1500 m"

Fig. 6

Horizontal (a) and across-front (b) distributions of EPV. (a) The vectors show the horizontal velocity at 5-m depth. The region of -90°<ϕRi<-45° is denoted by the thin gray contours. Topography is shown by the thick black isobaths at 200 and 1500 m, respectively. The across-front section is indicated by the pink line. (b) Density is shown by the black contours"

Fig. 7

Frontal spatial distribution of vertical velocity w′ at 50-m depth (a), and cross-front structure of vertical secondary circulation (b). Topography is shown by black isobaths of 1500 m in (a). (b) The along-front velocity u′ (shading) is positive for westward velocity. The vectors show lateral velocity v′ (m·s-1) and vertical velocity w′ (m·d-1). Potential density is denoted by black contours"