Seasonal variability of sea surface height in the South China Sea observed with TOPEX/Poseidon altimeter data

TOPEX/Poseidon altimeter measurements along 16 ground tracks in the South China Sea from November 1992 to October 1997 were used to observe the seasonal variability of sea surface height (SSH). In winter (November, December, January, and February) the SSH images are generally characterized by a sea surface tilting downward toward the east. High sea levels on the western side of the sea have a little monthly change, and a low (minus) sea level peak is centered in the northeastern deep basin. In spring (March and April), a single high sea level peak (HP) centered at 14°N, 114°E becomes a dominant feature. In summer (May, June, July, and August) the SSH images show a sea surface tilting downward toward the west. The HP moves from 14°N, 114°E in May to the northwest of Luzon Island in July. Low sea levels are centered in the offshore of the northern and southern Vietnamese coast. In fall (September and October) the appearance of an eastward low sea level jet in the western basin between 12° and 14°N constitutes a major feature of the SSH images. These results are comparable with previous results and drifter measurements.