Anisotropic energy transfers and vertical layering in stably stratified turbulence

We simulate stably stratified turbulence with vortical forcing, and compute directional energy fluxes from a spectral region with 0≤k⊥≤k and 0≤k∥≤k, where k⊥ and k∥ are horizontal and vertical wavenumbers, respectively. We observe that at increased stratification, the energy fluxes of the kinetic and potential energies are significantly more pronounced along k∥-direction. We also study energy transfers by pressure and buoyancy and find that at strong stratification, these transfers predominantly take place along k∥-direction, whereas k⊥ remains in the vicinity of the forcing wavenumber kf. This anisotropic energy transfers and cascade lead to the vertical layering of thin, horizontally elongated structures.