| The Kuroshio is a north-flowing boundary current on the west side of the NorthPacific Ocean. It is characteristically fast, intense, deep and narrow, with relatively highertemperature and salinity. The Kuroshio Current (KC) plays a crutial role in the China’soffshore circulation, heat and salt transport, interaction among processes with differentscales. In addition, it’s annual and interannual variation exserts significant influenceover climate variability in China. In this work, the Regional Ocean Modeling System(ROMS) is adopted to study the influence of KC on the circulation in the China Sea, withspecial effort being paied to the Taiwan Warm Current and Tsushima Warm Current, theseasonal and interannual variation of volume transport through Luzon Strait (LS). In theend, a preliminary study is made on the influence of tides on the circulation in the ChinaSeas.A set of climatology simulation using ROMS is conducted to study the seasonalvariation of the circulation in the China Seas. The KC is the most (least) intense and widein summer (winter). The Taiwan-Tsushima Warm Current system is most significant insummer, while is it relatively weak in autumn. It is also found that the Taiwan WarmCurrent as well as the Tsushima Warm Current bears dual-core structure, which isstronger in summer compared to that in winter. The surface circulaton in the South ChinaSea (SCS) is controlled by the overlying monsoon system.In order to study the influence of the KC on the circulation in the China Seas,volume transports through three transections are analized, in addition to which thecorrelation between net volume transport to the East China Sea and ENSO is also studied.It is shown that the volume transport through PN transaction reaches the maximum(minimum) of27.2(23.1) Sv in summer (winter). Similarly, the volume transport through Taiwan Strait maximizes in July with a value of3.18Sv, while it minimizes in Decemberwith a value of1.19Sv. On the other hand, there is a net volume transport through KoreaStrait from the East China Sea to the Janpan Sea, with the maximum and minimum valueof2.92and1.05Sv, respectively. The volume transport through200m isobaths, which islargerly dominated by the KC, maximizes in winter with a value of3.57Sv, while itminimizes in summer with a value of0.03Sv. Statistic analysis demonstrates that the netvolume transport into the East China Sea correlates positively with ENSO with a certainphase lag.LS is the main channel, through which the SCS exchange water with the WestPacific Ocean. To investigate the influence of KC on the circulation in the SCS, threetransections along120,120.5and121°E are selected. The seasonal and interannualvariation of LS transport is calculated afterward. It is shown that the transport is from theWest Pacific Ocean to the SCS in the southern part of the strait with the maximum insummer, while it is from the SCS to the West Pacific Ocean in the northern part with themaximum in winter. Multi-core structure is a characteristic of the vertical transportpattern in the LS, with several cores in its southern part and only one core in its northernpart. The transports through three seleced transections maximize (minimize) in June(December), which is closely related with the remote influence of ENSO.In the end, the influence of tides on the circulation the the China Seas is analized. Itis found that tides exsert significant influence on the Taiwan Warm Current as well as thenorthward current in Changjiang estuary in summer. Along the transaction of32°N,vertical mixing is intensified in the upper layer, while significant upwelling is induced indepth. |
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