Penetration of a Vortex Lattice into the Bulk of a Liquid

Penetration of a vorticity lattice formed by waves propagating on the surface at an angle to each other into the bulk of a liquid is studied experimentally. It is shown that along with the Stokes drift it is necessary to regard nonlinear wave interaction in order to explain experimental time dependences of average vorticity. Vorticity distribution over the depth of a liquid is described by a sum of two exponents considering the contribution of both mechanisms. It is determined that formation of large-scale vortex flows leads to deformation of a vortex lattice and a decrease in an average value of the amplitude of lattice vorticity as a result of its drift.