Geomagnetic pulsations caused by the magnetopause oscillations (Comparison of spacecraft and geomagnetic observations)

Abstract

This paper is devoted to the study of long-period geomagnetic pulsations recorded after abrupt changes of the solar wind (SW) dynamic pressure. Data of simultaneous satellite observations within the “INTERBALL” program are used in the analysis of the magnetopause location and plasma and magnetic field parameters near the magnetopause. Geomagnetic pulsations are analyzed using data from several meridional chains of stations located in different longitudinal sectors. It is shown that experimental data confirm the Mishin's (1993) model of the excitation of damped radial oscillations of the magnetopause by SW pressure impulses that are recorded on the ground in the form of global geomagnetic pulsations. The period of these pulsations is proportional to the subsolar radius of the magnetosphere to the 4th power. It is shown that the pulsation period varies with time inversely as the sign of density variation. This is consistent with the Mishin's (1993) model.