Salinity Variations over Zhejiang Province Waters, China

摘要

In this article, we analyzed the monthly, seasonal and annual salinity variations and their relations with sea surface temperature (SST), rainfall over the Zhejiang province from 2005 to 2017. SST and rainfall were chosen as the main influence factors. There is an inverse relationship between rainfall and salinity. And the SST has a positive relation with salinity, showing slightly seasonal difference. The vertical variation is chec ked from surface to 150 meter depth, and 50 m is suggested to be a separating layer for salinity variations. We found that monthly changes in salinity are more variable in seawater at different depths. Seasonal changes in salinity in this area are significant. In winter and spring, the temperature is low, evaporation is small, and there is little rainfall, resulting in relatively higher salinity; frequent typhoon in summer and autumn with a large amount of freshwater input from the Yangtze River causes a lower salinity. For annual changes, we found an increasing trend over the surface as well as in sub-surface. In addition, we found initially that the stratification of the saline waters in Zhejiang Province makes the sub-surface salinity higher.