Wave-vector dependence of magnetic turbulence spectra in the solar wind

Direct measurements of wave number spectra are presented for three distinct fluctuation components in the solar wind: two-dimensional, Alfven-like, and compressible turbulence. These three modes uniquely describe magnetic fluctuations in general and are applied to interpreting turbulent magnetic fields in the solar wind. The measurement makes extensive use of the four Cluster spacecraft and enables us to determine the spectra as well as the energy contributions of the three modes at various wave numbers. We find that the two-dimensional component contributes 60-70% of energy. It spectrum is characterised by the spectral index -5/3. The Alfven-like component contributes 20-30% and has spectral index -2. The compressible component contains at most 10% in energy.

@article{id1264,
  author = {Narita, Y. and Glassmeier, K.-H. and Gary, S. P. and Goldstein, M. L. and Treumann, R. A.},
  journal = {Physical Review Letters},
  language = {en},
  note = {Experimental, Observation of the properties of plasma turbulence},
  pages = {11 pages},
  title = {Wave-vector dependence of magnetic turbulence spectra in the solar wind},
  year = {2008},
}

%O Journal Article
%A Narita, Y.
%A Glassmeier, K.-H.
%A Gary, S. P.
%A Goldstein, M. L.
%A Treumann, R. A.
%J Physical Review Letters
%G en
%O Experimental, Observation of the properties of plasma turbulence
%P 11 pages
%T Wave-vector dependence of magnetic turbulence spectra in the solar wind
%D 2008