Fig. 1

Typical circulations in the South China Sea in winter (top) and summer (bottom), using AVISO altimeter data(https://www.aviso.altimetry.fr/en/data/ data-access.html)"

Fig. 2

Satellite observation (a); numerical simulation (b); in-situ observations (c, d), and analysis of water masses (e) for upwelling in the northern South China Sea. After Jing et al (2011, 2015)"

Fig. 3

South China Sea monsoon anomaly (a); atmospheric circulation anomalies in the western Pacific, South China Sea and East Indian Ocean (b) in the summer of 1998. In (b), shading denotes SST anomalies, contour denotes latent heat flux anomalies, and vectors are atmospheric circulation anomalies on 850 hPa. After Jing et al (2011)"

Fig. 4

Map of water depths overlapped with CTD stations (dots). S1, S2, S3, and S4 denote the names of CTD transects. The numbers indicate sampling stations (skipping some for visual clarity)"

Fig. 5

Cluster analysis of the environmental elements at the sampling stations. The first number of the sample name (say S411500) denotes transect number, the second and third numbers denote station number, and the last three numbers indicate sampling depths. After Zhang (2016)"

Fig. 6

Bacterial diversity at 25 and 50 m along transect S1 (a) and at 50 m along transect S3 (b). The size of each bubble represents the Shannon index of diversity"

Fig. 7

Bacterial community compositions at different depths of the sampling stations:transect S1 (a); transect S3 (b) and transect S4 (c). The pie charts denote the relative abundances of different groups"

Fig. 8

Annual-mean SST gradients and wind speeds from Satellite observations (a); in-situ observations (b) and vertical structures of temperature and salinity in the representative sections (c-h) for the fronts in the northern South China Sea. The thick black lines in (c-h) denote isopycnic surface with ${{\sigma }_{\theta }}=23$, which approximately reflect the variation of thermocline. After Jing et al (2015)"

Fig. 9

Distributions of sea level anomalies and geostrophic velocity anomalies during the cruise, overlapped with sampling stations (black dots) and station numbers. After Zhang et al (2018)"