A study of stability of two-gyre flow pattern on a rotating sphere

研究了均匀东风作用下具有刚性边界的旋转球体上一个区域内的正压流动，并观察到了双旋流态。随着风强迫的增加，定常的西向气流通过Hopf分叉加强而产生振荡不稳定。由于风力较强，每个涡旋都会形成一个涡街。随着流场尺寸的增大，南北两个涡街的数量增加。对于有进有出的定常流动，观测到了向西的加强。

We study the barotropic flows in a domain on a rotating sphere with the rigid boundary under a uniform easterly wind, and observe two-gyre flow patterns. As wind-forcing increases, an oscillating instability arises from the steady flow of westward intensification by Hopf bifurcation. As wind-forcing is strong, a vortex street occurs from each gyre. As the size of the fluid field is larger, the number of the north and the south vortex streets increases. The westward intensification is observed for steady flow with inflow and outflow.