Influence of Intermittency on the Energy Transfer Rate of Solar Wind Turbulence

Abstract

The intermittency in the solar wind turbulence manifests itself in the anisotropic scaling due to the anisotropic spectral index and the intermittent level based on the extended P model. However, the influence of intermittency on the energy transfer rate remains unclear. Here we apply the partial variance of increments method to identify the intermittency for the magnetic field measurements in the fast solar wind from the Ulysses spacecraft. We distinguish the sampling direction using the angle θ RB between the local magnetic field and radial direction to study the anisotropy. We perform the multiorder structure function analyses and adopt the log-Poisson cascade model to describe the role of intermittency in the cascade process. We find that the anisotropy of the scaling becomes isotropic with a complete removal of intermittency. We compare explicitly the anisotropy of the energy transfer rate before and after removing the intermittency for the same interval for the first time. We find a distinct anisotropy with a cascade enhancement in the direction perpendicular to the local magnetic field. The removal of the intermittency greatly weakens the anisotropy by mainly reducing the perpendicular energy transfer rate. Our findings suggest that the intermittency effectively enhances the energy transfer rate, in particular in the perpendicular direction in the solar wind turbulence.