Electromagnetic field of a solar wind in the Earth magnetosphere

Consideration is given to the solar wind energy transfer through the magnetopause into the Earth's magnetosphere on the basis of a hydrodynamic model. A problem has been solved for a high-conductive liquid flow around an obstacle with the typical dimension D. It is shown that at the distance from the head L = Msub(A)D, where Msub(A) is the Alven Mach number, one can observe penetration of a field from the flux into the streamlined body. The results obtained were applied to the solution of the problem of Solar wind -magnetosphere interaction, where Msub(A) > > 1. The penetration of the interplanetary magnetic field into the magnetosphere tail leads to a continuous ''build-up'' on its surface of open lines of force and, hence, to a higher magnetic energy of this field. The paper assesses the rate of the magnetic flux build-up in the tail prior to a substorm and the rate of the magnetic energy storage