Local-flux vectors of conserved quantities in wavenumber space: Anisotropic structures in Charney–Hasegawa–Mima turbulence

Abstract

Heterogeneous coexistence turbulence (HCT) with anisotropic wave turbulence and isotropic vortex turbulence includes a transition range beyond the application limits of cascade theory and weak turbulence theory. Local-flux vectors, formulated based on scalar potential functions, of conserved quantities in the wavenumber space quantify their directional properties. Two balance types, time and term, make up the idea of critical balance, which the proposed local-flux vectors can quantitatively evaluate. The local-flux vectors reveal anisotropic fluxes along the wavenumbers deduced from the critical balance as well as energy-enstrophy double cascade in HCT of Charney-Hasegawa-Mima model.