Geomagnetic Pulsations in the Polar Cap

Abstract

Properties of polar cap pulsations of discrete type occurring sporadically (IPRP, Pc 1b) and regularly observed around noon (ipcl, Pc 1-2) are described. The character of their dependence on Kp, their diurnal variation, and other morphological properties are used to determine the position of the dayside cusp, and the dynamics of its shifting on latitude. Recent observations of parameters of the regions of the outer magnetosphere are used for suggestions of possible mechanisms of generation of these pulsations. Briefly are outlined the characters of behaviour in the polar cap of well known pulsations of Pc 3, Pc 4, and Pi 2 types.