Simulating summer circulation and water exchange in the Beibu Gulf

Abstract

A cyclonic gyre and a semi-closed anti-cyclonic gyre exist respectively in the north and south of Beibu Gulf. Water exchange is calculated using tracer-tracking model in FVCOM via adding an imaginary conservative material as the tracer material. After circularly using the wind condition of August 2012 for 800days, we get spatial and temporal distribution of the tracer concentration of Beibu Gulf of summer in 2012. Forced by circulation, Qiongzhou Strait, Da Nang sea area and Sanya sea area are main mass transport galleries of Beibu Gulf. The half exchange period of the Beibu Gulf in summer is 518 days while the value of average residence time is 588 days. Considering that summer lasts for 3 months, water exchange rate of the whole gulf is 13.73%.