A Quasilinear Dynamics of Pc-1 Geomagnetic Pulsations (Pearls)

A development of ion-cyclotron instability is simulated by numerical procedure on a basis of quasilinear theory. Particle and wave losses are taken into account. The diagrams included in this paper show variations of wave spectrum with time. Maximal wave amplitudes for different magnetospheric conditions in the region of Pc-1 generation are found to vary from -10 to -100mγ and duration of the event (an interval with square amplitude being greater than a half of maximum) from -7min to -70min. This data were used to verify an approximate expression which connects amplitude and duration of emission with initial parameters of plasma.