Anisotropy and intermittency in drift-wave turbulence with zonal flows: a two-dimensional continuous wavelet analysis

We examine anisotropy and spatial intermittency at small scales in drift-wave turbulence with zonal flows. We use a two-dimensional directional continuous wavelet transform, which allows simultaneous localization in scale, position, and direction. This wavelet analysis is applied to vorticity fields obtained from numerical simulations of the modified Hasegawa–Wakatani model, a reduced model of resistive drift-wave turbulence in magnetized plasmas with zonal flows. Directional wavelet statistics characterize the anisotropy of the turbulence. The second-order moment is enhanced around directions perpendicular to the zonal flow. Spatial intermittency, characterized by scale-dependent flatness, is more pronounced around directions along the zonal flow.