Summer Upwelling in the Northern Continental Shelf of the South China Sea

Abstract

Summer upwelling system in the northern continental shelf of the South China Sea (NCSCS) is investigated with the Pathfinder, Advanced Very High Resolution Radiometer (AVHRR) Sea Surface Temperature (SST) from satellite observation, and a three-dimensional baroclinic nonlinear numerical model forced by QuikSCAT winds. The AVHRR observation and modeling results have shown the summer upwelling is a regular phenomenon during June-September in the NCSCS. The surface and subsurface water status demonstrates continental shelf upwelling characteristics obviously, such as lower temperature, higher salinity and higher potential density in the east of the Hainan Island, the east of the Leizhou Peninsula and the southeast of the Guangzhou Bay (Qiongdong Upwelling), and the inshore areas from the Shantou Coast to the Nanri Islands of Fujian Coast (Yuedong Upwelling). The centra of the upwelling are mostly located in 111°10′E、19°45′N between the Qinglan Bay and the Qizhou Archipelagoes of eastern Hainan Island, 110°15′E、18°25′N near the Lingshui Bay, 116°45′E、22°50′N of the Shantou Coast and 118°E、23°40′N near the Taiwan Shoal. It is also found that the upwelling areas and centra from modeling results are in agreement with the AVHRR SST.