This paper concerns the question of whether the maximum Earth ring current strength exists and at which moment the ring current can start to break up, thus making a new mechanism of the ring current decrease during the magnetic storm. We study this effect using the Stormer theory of particle motion. After transition of critical strength, Stormer's inner trapping region opens up and the ring current charged particles get the opportunity to leave it, thus decreasing the current strength.

In the present work we used unique data on the magnetic field in the Jovian magnetosphere measured by the Juno spacecraft. The data allowed us to determine optimal parameters of the magnetodisc in the paraboloid magnetospheric model and find the ways to qualitatively improve the model.

The paraboloid model of Saturn’s magnetosphere describes the magnetic field of the planet, the ring current, magnetopause current, and the tail current. The model parameters are determined by comparison with the Cassini magnetic field data from 18 near-equatorial passes that span wide ranges of LT. The best-fit model parameters are employed to determine how the parameters vary with the subsolar distance of the magnetopause, governed by pressure balance at the magnetospheric boundary.