The Phenomenon of Negative Viscosity During the Stretching of Synoptic Ocean Eddies by Barotropic Currents

An ensemble of synoptic oceanic vortices, which is influenced by background currents, can be represented as the quasi-two-dimensional mesoscale turbulence. The evolution of vortices in an ensemble can occur according to several scenarios: 1) initial merging of closely spaced vortices of the same name; 2) periodic or quasi-periodic evolution of horizontal dimensions with their limited change; 3) unlimited stretching of vortices in the horizontal plane. The work is aimed at demonstrating the possibility of negative viscosity manifestation in the defined water areas of the World Ocean at the stage of unrestricted stretching of mesoscale vortex structures by horizontal inhomogeneous currents. The reason for the manifestation of negative viscosity in such a system is associated with the loss of energy of the elongated vortices and its redistribution into background currents.