Laboratory 2.2. of Mathematical Models of Near Space
Collaboration with Space Research Institute of the Austrian academy of Sciences.
In a framework of collaboration with the Austrian academy of sciences,
several aspects of mathematical modelling of space plasma
- Magnetohydrodynamic (MHD) models of the solar wind flow around planets (Earth, Venus, Jupiter, Saturn), and magnetic clouds.
- A dissipative nonsteady MHD model is elaborated for reconnection of magnetic field lines in cases of nonhomogeneous plasma resistivity.
- Mathematical modelling is performed for the slow magnetosonic and Alfven waves propagating along the narrowing and curved magnetic flux tubes which are typical ones for the magnetospheres of planets.
- MHD instabilities are studied for thin magnetic layers characterized by a finite curvature radius.
With regard to the solar wind flow around planets and magnetic clouds,
the enhanced magnetic field regions were studied which were
called «magnetic barrier».
The magnetic barrier is a thin layer adjacent to the sunward
side of the magnetospheric boundary which
contains an enhanced magnetic field originating from the interplanetary
magnetic field. This layer
accumulates magnetic energy which is generated by the solar wind flow
because of magnetic field stretching in front of the magnetosphere
(magnetic field line draping).
It may thus act as a reservoir for magnetic field reconnection.
The magnetic barrier is characterized by a decreased plasma pressure which
becomes much less than the magnetic pressure.
The thickness of the magnetic
barrier is inversely proportional
to the Alfv'en-Mach number squared. A scale of the magnetic energy
variation in front of the magnetosphere is of the same order as the magnetic
barrier thickness. The magnetic field plays a dominant role near by the
magnetospheric boundary where the magnetic forces strongly affect
the plasma flow
pattern. This influence of the magnetic field results in the formation of the
stagnation line flow pattern at the dayside magnetospheric boundary,
different from the stagnation point flow which is typical of hydrodynamic flow past a blunt
The magnetic barrier forms the background for the analysis of dissipative processes, magnetic field line reconnection, and instabilities at the magnetospheric boundary.
of the solar wind flow models deal with the anisotropy of plasma pressure in a magnetized plasma
In the case of anisotropy, the plasma
pressure is a tensor with
different parallel and perpendicular components relative to the
magnetic field. The ratio of the perpendicular and parallel pressures
is an unknown
parameter and an additional relation is required in order
to close the anisotropic MHD system of equations.
Variety of the closure relations have been analyzed
and the results have been compared with space probe