Problem description:
What is coastal current?
Analysis:
China coastal current
One of the current systems along the coast of China. It is mainly composed of Yellow Sea coastal current, East China Sea coastal current and South China Sea coastal current. The coastal current of the Yellow Sea is diluted water flowing along the coast of Shandong and Jiangsu, which belongs to low salt (low temperature in winter) and the water color is turbid. It starts in Bohai Bay, flows eastward along the northern shore of Shandong Peninsula, bypasses Chengshanjiao, goes south along the outer edge of Haizhou Bay, and turns from the north of the Yangtze River estuary to the southeast. Part of it flows into the Yellow Sea Warm Current, and the other part flows into the East China Sea through the Yangtze Estuary Shoal, with a velocity generally less than 25 cm/s. The coastal current in the East China Sea is a mixture of runoff from the Yangtze River, Qiantang River and Minjiang River and the surrounding seawater. The salinity is extremely low, the water temperature changes greatly every year, and the water color is turbid. The flow velocity is about 25 cm/s, and the flow direction changes with the seasons: in winter, the coastal edge flows south because of the prevailing northeast wind, and in summer, it flows north and northeast because of the southeast wind and southwest wind. The coastal current in the South China Sea refers to the current along the coast of Guangdong to the west of east longitude 1 16. The salinity is relatively low (the lowest salinity in summer is only 1.2‰), and the velocity is relatively high, with an average of 25cm/s and a maximum of 70cm/s near the Pearl River estuary. The flow direction also changes with the prevailing seasonal wind: in winter, it flows southwest along the coast of Guangdong to Zhanjiang Port and southward along Leizhou Peninsula, and it is divided into two streams, one of which continues to flow southwest along the east coast of South Island, and the other turns northeast at Hainan Island, forming Zhanjiang Port circulation. It flows from Zhanjiang Port to the northeast in summer.