Interaction between an upper-layer point vortex and a bottom topography in a two-layer system

In this paper, the interaction between an upper-layer vortex and a bottom topography is investigated using $f$ -plane two-layer quasi-geostrophic model with point step-like topography. The contour dynamics method used to formulate model. A steadily propagating linear solution along topography, known as pseudoimage solution, derived analytically for weak vortex, nonlinear obtained numerically. Numerical experiments show that collapses time. Saddle-node points in velocity field are critical collapse. Even after collapse, propagates similarly solution. various initial conditions has two types of motion system: away from latter case, lower-layer potential vorticity anomaly form heton-like dipole structure. classification results anticyclonic (cyclonic) on deeper (shallower) side more likely structure than cyclonic (anticyclonic) when their distance same.