Cascade Processes in Rapid Rotation

Resumo

The process of the kinetic energy and kinetic helicity transfer over the spectrum in an incompressible, rapidly rotating turbulent medium is considered. An analog of the Fjortoft theorem for 3D turbulence is proposed. It is shown that, similar to 2D turbulence, there are two cascades simultaneously: the inverse cascade of the kinetic energy and the direct cascade of the kinetic helicity, which in the case of 2D turbulence corresponds to the cascade of enstrophy. The result is in agreement with our earlier calculations, some recent numerical simulations, and physical experiments on geostrophic turbulence. The proposed scenario is applicable to explain the processes in the liquid cores of planets and fast-rotating stars.