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Cascade rates of magnetohydrodynamic turbulence in the solar wind (SOLWINDCAS)
Date du début: 1 mars 2012, Date de fin: 28 févr. 2014 PROJET  TERMINÉ 

"Turbulence is one the most important unsolved problems of classical physics. Plasma occurs in states of turbulence under a wide range of conditions including space and astrophysical plasmas as well as those produced in laboratory confinement devices. Magnetohydrodynamics (MHD) is the simplest fluid approach to study plasma dynamics. MHD turbulence takes place in many practical applications (solar atmosphere, interstellar medium etc.). Due to this reason MHD turbulence has been intensively studied during the last several decades theoretically as well as by means of high resolution direct numerical simulations. Currently there exist more than ten different theoretical models of anisotropic MHD turbulence. With an abundance of in situ spacecraft measurements, the solar wind is a unique natural laboratory that can be used to test theories and improve our understanding of the basic mechanisms involved in MHD turbulence. Presented project implies the study of cascade rates in the solar wind turbulence using generalized Yaglom’s relation, for determination of the role of MHD turbulence in the solar wind heating, and for testing predictions of various theoretical models of MHD turbulence. The objectives of the presented project are: (i) Derivation of the generalized Yaglom’s relation for MHD turbulence taking into account the effect of expansion of the solar wind; (ii) determination of the role of MHD turbulence in the solar wind heating applying generalized Yaglom’s relation to the data of the solar wind fluctuations; (iii) determination of the relation between the energies and energy dissipation rates for the fast and slow solar wind data and comparison of the obtained results with the predictions of different theoretical model of MHD turbulence; (iv) to derive the analogue of the spectral pinning effect for MHD turbulence in case of kinetic dissipation and to apply it for the study of the solar wind data"