ИСТИНА

We study possible structures, both steady and unsteady, that can move without significant change of their shape in compressible barotropic fluid. Since the horizontal scale of the atmosphere is much more larger than the vertical one, the initial primitive three-dimensional system of equations can be reduced to a two-dimensional one, using a special procedure of averaging over the height. Thus, the equations of two-dimensional compressible fluid on a rotating plane present our main interest. Most important structure that can exist for a long time in such kind of model is a steady or almost steady vortex. It can be associated with a tropical cyclone. Nevertheless, there are another interesting non-smooth structures that can be associated with cyclone containing frontal zones.