HR: 1340h
AN: SH23A-1163    [Abstracts]
TI: The inertial range of MHD turbulence and Hall MHD turbulence in solar wind
AU: * Carbone, V
EM: carbone@fis.unical.it
AF: Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, Rende (CS), 87036, Italy
AU: Sorriso-Valvo, L
EM: sorriso@fis.unical.it
AF: LICRYL - CNR/INFM, Ponte P. Bucci, cubo 31C, Rende (CS), 87036, Italy
AU: Servidio, S
EM: servidio@fis.unical.it
AF: Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, Rende (CS), 87036, Italy
AU: Alexandrova, O
EM: olga.alexandrova@obspm.fr
AF: LESIA/CNRS - Observatoire de Paris, 5 pl. J. Janssen, Meudon, 92195, France
AU: Marino, R
EM: rmarino@fis.unical.it
AF: Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, cubo 31C, Rende (CS), 87036, Italy
AU: Noullez, A
EM: anz@obs-nice.fr
AF: Observatoire de la Cote d'Azur - Nice, Bd de l'Observatoire, Nice, 04300, France
AB: Turbulent fluctuations within solar wind spectrum follows nearly Kolmogorov's power law spectrum below the ion cyclotron frequency f_ci. Above this frequency, the observed steeper power law is believed to be a 'dissipative range' of the solar wind turbulence. The inertial range is studied here in terms of the pseudo-energy flux, which can be shown to have a linear scaling law in isotropic, homogeneous, fully developed turbulence. Such linear scaling has recently been observed in polar wind measured by Ulysses, and represent a strong evidence that a nonlinear, turbulent cascade is at work in the solar windplasma. Moreover, we analyze magnetic field fluctuations measured onboard Cluster, lasting two decades above f_ci. Well defined power law and a strong increase of intermittency with frequency in this range indicates that turbulence cannot be characterized by a 'dissipative range'. Rather we conjecture that the presence of dispersive effects is responsible for a steepening of the spectral energy density, simply because a cascade can be realized in a time that is shorter than the usual eddy- turnover time. In the Hall MHD formulation magnetic power depends on the degree of plasma compressibility. Such results are compared with numerical smulation of Hall MHD.
DE: 4490 Turbulence (3379, 4568, 7863)
DE: 7836 MHD waves and instabilities (2149, 2752, 6050)
DE: 7863 Turbulence (4490)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting