Scaling laws in Hall inertial-range turbulence


There is an increasing amount of observational evidence in space plasmas for the breakdown of inertial-range spectra of magnetohydrodynamic (MHD) turbulence on spatial scales smaller than the ion inertial length. Magnetic energy spectra often exhibit a steepening, which is reminiscent of dissipation of turbulence energy, for example in wave-particle interactions. Electric energy spectra, on the other hand, tend to be flatter than those of MHD turbulence, which is indicative of a dispersive process converting magnetic into electric energy in electromagnetic wave excitation. Here we develop a model of the scaling laws and the power spectra for the Hall-inertial range in plasma turbulence. A phenomenological approach is taken. The Hall electric field attains an electrostatic component when the wave vectors are perpendicular to the mean magnetic field. The power spectra of Hall-turbulence are steep for the magnetic field with slope of -7/3 for compressible magnetic turbulence, they are flatter for the Hall electric field with slope -1/3. Our model for the Hall-turbulence serves as a likely candidate to explain the steepening of the magnetic energy spectra in the solar wind neither as indication of the dissipation range nor the dispersive range but as the Hall-inertial range. Our model also reproduces the shape of energy spectra in Kelvin-Helmholtz turbulence observed at the Earth magnetopause.

  author = {Narita, Y. and Baumjohann, W. and Treumann, R. A.},
  doi = {angeo-37-825-2019},
  journal = {Annales Geophysicae},
  language = {en},
  pages = {825-834},
  title = {Scaling laws in Hall inertial-range turbulence},
  volume = {37},
  year = {2019},
%O Journal Article
%A Narita, Y.
%A Baumjohann, W.
%A Treumann, R. A.
%R angeo-37-825-2019
%J Annales Geophysicae
%G en
%P 825-834
%T Scaling laws in Hall inertial-range turbulence
%V 37
%D 2019