Permalink : http://hdl.handle.net/2115/64174

JaLCDOI : 10.14943/bull.fish.66.3.99

KEYWORDS : Soya Warm Current;anti-clockwise nonlinear eddy street;conservation of potential vorticity;self-excited oscillation

The generation mechanism of anti-clockwise nonlinear eddy street along the Soya Warm Current is examined using the inflow-forced numerical model incorporating the simple shelf-slope topography. According to the conservation of potential vorticity, a strong positive vorticity is produced off the inflow entrance by vortex stretching as the water column is pushed out to deeper offshore. It rapidly grows up an isolated anti-clockwise circular eddy, i.e., a nonlinear eddy, during advection time traveling round the eddy. Therefore, this advection time controls the oscillated period, and each isolated eddy is periodically generated and stably advected downstream by the mean shear-flow. Such flow system accompanied by the eddy street is interpreted as the self-excited oscillation.