局地风急流对缺口处西边界流流径的影响

The impact of local wind stress on the path of the west boundary current flowing through a gap

基于缺口处的西边界流流态存在迟滞回归现象,使用1.5层约化重力浅水模式,研究了受山脉与地形影响的局地风急流对西边界流流径的影响。结果显示,在西边界流从跨越态向入侵态转变的临界状态,局地的西向和南向风应力能够使西边界流向入侵态转变,局地的东向和北向风应力不能使其发生转变;在西边界流从入侵态向跨越态转变的临界状态,除西风以外的风应力都能使西边界流向跨越态转变。此外数值实验还表明风应力旋度的作用强于风应力大小的作用。

Based on the hysteresis phenomenon of the west boundary current（WBC） flowing through a gap, the impact of the local wind rushing which was influenced by the mountains and topography on the path of WBC was studied using a 1.5-layer reduce-gravity shallow water model. The results showed that the local east and north wind could induce the WBC changing from the leap state to the penetration state but the west and south wind could not when the WBC wasat the critical statefrom leap to penetration.The results also showed that the wind from all direc-tions except west could induce the change of WBC from the penetration state to the leap state. Analysis also showed that the wind stress curl had a stronger impact on the changing of WBC than the size of the wind stress.