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

The intermittency in the solar wind turbulence influences the anisotropy of the spectral index and the scaling of multiorder structure functions. However, its influence on the energy transfer rate remains unclear. Here we identify the intermittency using the partial variance of increments method for the magnetic field data measured in the fast solar wind by the Ulysses spacecraft. We study the anisotropy by distinguishing the sampling direction using the angle θRB between the local magnetic field and radial direction. We analyze the multiorder structure function analyses  and describe the role of intermittency in the framework of log-Poisson cascade model. We find the isotropic scaling with a complete removal of intermittency. We compare explicitly the anisotropy of the energy transfer rate before and after removing the intermittency 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.