Spectrum of kinetic-Alfvén turbulence

Abstract

A numerical study of strong kinetic-Alfvén turbulence at scales smaller than the ion gyroscale is presented, and a phenomenological model is proposed that argues that magnetic and density fluctuations are concentrated mostly in two-dimensional structures, which leads to their Fourier energy spectra E(k ⊥)k -8/3⊥, where k ⊥ is the wavevector component normal to the strong background magnetic field. The results may provide an explanation for recent observations of magnetic and density fluctuations in the solar wind at sub-proton scales. © © 2012. The American Astronomical Society. All rights reserved.