2011/11/23 by Olga Alexandrova, C. Lacombe, Alexandrova, O. +5
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #FOS: Physical sciences #Geomagnetism and Paleomagnetism Studies #Ionosphere and magnetosphere dynamics #Plasma Physics (physics.plasm-ph) #Solar and Space Plasma Dynamics #Solar and Stellar Astrophysics (astro-ph.SR) #Space Physics (physics.space-ph)
paper · pdf · doi:10.48550/arxiv.1111.5649
openalex publication_date 2011/11/23 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The turbulent spectrum of magnetic fluctuations in the solar wind displays a spectral break at ion characteristic scales. At electron scales the spectral shape is not yet completely established. Here, we perform a statistical study of 102 spectra at plasma kinetic scales, measured by the Cluster/STAFF instrument in the free solar wind. We show that the magnetic spectrum in the high frequency range, [1,400] Hz, has a form similar to what is found in hydrodynamics in the dissipation range ~Ak^(-α)exp(-kld). The dissipation scale ld is found to be correlated with the electron Larmor radius ρe. The spectral index αvaries in the range [2.2,2.9] and is anti-correlated with ld, as expected in the case of the balance between the energy injection and the energy dissipation. The coefficient A is found to be proportional to the ion temperature anisotropy, suggesting that local ion instabilities may play some role for the solar wind turbulence at plasma kinetic scales. The exponential spectral shape found here indicates that the effective dissipation of magnetic fluctuations in the solar wind has a wave number dependence similar to that of the resistive term in collisional fluids ~k2δB.