Propagation of Pc3?4 pulsations at low latitudes

Abstract

Magnetic pulsations are ultra-low frequcncy (ULF) oscillations in the geomagnetic field with periods of the order of 1?1000s. These pulsations are manifestations of hydromagnetic waves gencrated in the magnetosphere by a variety ofphysical processes and instabilities. Pc3?4 waves fall in the period range 10?150 s and appear to be produced by resonant oscillations of the earth's magnetic field lines, generally driven by the solar wind as it flows around the magnetosphere. Figure 1 shows a schematic representation of these iriteraclion regions.