  Using the many-year observations at several high-latitude observatories in
the Northern and Southern Hemispheres, the regularities in distribution of
magnetic impulse events (MIEs) amplitudes are studied. It is shown that the
tails of the functions of statistical distributions of impulse amplitudes are
approximated by a power function of the form f (A) = A**(-b), where A is the
impulse amplitude, and b is the power index laying in the range from 1 to 5.
Experimental confirmation is obtained to the hypothesis suggested earlier that
the impulse generation regime qualitatively corresponds to the model of on-off
intermittency. It is assumed that the model of the on-off intermittency may be
considered as one of the possible mechanisms of MIEs generation. It is found
that the majority of the analyzed statistical distributions of MIEs amplitudes
have the index b exceeding 2, the fact being typical for chaotic regimes called
the strong turbulence. In some cases the index b is close to the unity, this
fact being typical for the regimes generated in weakly turbulized medium. The
results obtained make it possible to assume that: a) at higher magnetospheric
latitudes, the plasma turbulence degree is higher that at lower latitudes, b)
in the afternoon sector of the magnetosphere, the plasma is stronger turbulized
than in the prenoon sector; c) in the Northern and Southern Hemispheres the
magnetospheric plasma is stronger turbulized in summer and winter,
respectively; d) at the growth phase of solar activity the magnetospheric
plasma is stronger turbulized than at the declining phase. The dependence of
the power index b on the solar wind parameters and IMF demonstrates the
influence of interplanetary conditions on the high-latitude magnetosphere
plasma where MIEs are formed.

Space Physics;Geophysics