  This paper analyzes the consequences of electric current generation at the
front of the Bow Shock (BS) and the dependence of the direction of this current
on the IMF. The conditions of this current closure through the body of the
magnetosphere are discussed. It is shown that the process of penetration of the
external current into magnetized plasma has a two-stage character. Initially, a
change in current on the boundary gives rise to a region of surface charge, the
field of which polarizes the near-wall layer with the thickness on the order of
one gyroradius of protons. The polarization process involves the formation of
the displacement current which produces the Ampere force accelerating the
plasma inside the double layer. When the plasma velocity reaches the electric
drift velocity (within a time on the order of the inverse gyrofrequency of
protons), the electric field in this plasma disappears, whereas in a fixed
frame of reference, on the contrary, it reaches equilibrium values. The front
of variation of the electric field penetrates the plasma with the velocity of a
fast magnetosonic wave. A change in the convection velocity field causes a
redistribution of plasma pressure. The appearance of corresponding gradients
signifies the penetration of current into plasma. The gradients are changing
until a new steady state is reached, to which the new convection velocity field
and the new plasma pressure field correspond. This new state is reached in a
time which is estimated.
