Some estimates on the space scales of vortex pairs emitted from river mouths

Abstract

Abstract. Two-dimensional vortex pairs are frequently observed in geophysical conditions, for example, in a shelf zone of the ocean near river mouths. The main aims of the work are to estimate the space scales of such vortex structures, to analyze possible scenarios of vortex pair motion and to give the qualitative classification of their trajectories. We discuss some features of the motion of strong localized vorticity concentrations in a given flow in the presence of boundaries. The analyses are made in the framework of a 2D point vortex model with an open polygonal boundary. Estimations are made for the characteristic parameters of dipole vortex structures emitted from river mouths into the open ocean.

Cyclostrophic vortices in polar regions of rotating planets

“…Therefore, a given continuous vorticity distribution can be approximated by a step-function. The velocity in the fluid and, in particular, at the contours of vorticity-discontinuity can be found using the Green's function of the associated Laplace (or another) operator, or be using the method of pseudo-differential operators (Maslov, 1973;Goncharov and Pavlov, 2000). The equations of contour dynamics describe the selfinduced motion of the vorticity-discontinuity boundaries, or "contours," in an inviscid, incompressible, two-dimensional fluid whose vorticity distribution is piece-wise constant.…”

“…They are often used as the simplest models for geophysical and astrophysical flows (Dritschel and Legras, 1993;Frisch, 1995;Marcus, 1988;Sommeria et al, 1988;Pavlov et al, 2001;Goncharov and Pavlov, 2001).…”

“…We consider below quasi two-dimensional flows in a thin sheet of an ideal fluid, an assumption which allows one to make some additional simplifications (see Goncharov and Pavlov, 1997, 1998, 2000, and references therein).…”