Magnetosheath model in the Chew-Goldberger-Low approximation

Parameters of the solar wind plasma and magnetic field in the magnetosheath are calculated for an anisotropic plasma model in the Chew-Goldberger-Low approximation. It is shown that in the case when the energy transfer betwee n the perpendicular and parallel (with respect to the magnetic field) degre es of freedom is absent, the resulting temperature anisotropy may significa ntly affect the plasma density and magnetic field intensity profiles across the magnetosheath. However, in this case, the value of the temperature ani sotropy (the ratio of the perpendicular to the parallel component of the te mperature with respect to the magnetic field, T-perpendicular to/T-parallel to) becomes unrealistic high. To bring agreement between the model values of the temperature anisotropy and experimental data, the existence of an in tensive proton pitch-angle diffusion is assumed. In the case when the tempe rature anisotropy relaxation time is much smaller than the time taken by th e solar wind plasma to move from the bow shock to the magnetopause, one has T-perpendicular to/T(parallel to)approximate to 1, and the profiles of the magnetic field and plasma density along the subsolar stream line insignifi cantly differ from the profiles obtained for the isotropic magnetohydrodyna mic (MHD) model. In an intermediate case when the relaxation time is of the order of the plasma transport time, the value of T-perpendicular to/T-para llel to may amount to the values observed in the magnetosheath. (C) 1999 Am erican Institute of Physics. [S1070-664X(99)02807-4].