LIMITATION ON THE SIZES OF ENERGY-CONTAINING EDDIES IN QUASI-2-DIMENSIONAL FLOWS WITH BOTTOM FRICTION

Numerical simulations of the behavior of quasi-two-dimensional turbule nce with Rayleigh bottom friction included are carried out in the rang e of small wave numbers. It is shown that bottom friction is responsib le for the appearance of a limiting length scale such that the energy of quasi-two-dimensional turbulent motion is mainly concentrated in mo tions on smaller scales. The limiting length scale increases with forc ing intensity but more slowly than by the theoretical law Re-3/4, whic h was obtained under the assumption that the upscale energy cascade ra te is constant. Actually, due to the occurrence of dissipation on all the scales in the presence of bottom friction, the upscale energy casc ade rate does not remain constant. As a consequence, there is no inert ial range.