PC 3 Pulsations Observed at Two Conjugate Station Pairs Near the Cusp and Auroral Latitudes

In order to clarify the energy source and propagation mechanism of hydromagnetic waves in the magnetosphere, we examine Pc 3 magnetic pulsations simultaneously observed at two conjugate station pairs, South Pole Frobisher Bay and Syowa-Husafell, located near the cusp and at auroral latitudes, respectively. Through a dynamic spectral analysis, it is shown that the Pc 3 pulsations are observed over a wider azimuthal extent at an auroral zone location than at a location near the cusp. That is, at cusp latitudes the Pc 3 pulsations are preferentially observed around local noon, whereas they are simultaneously activated at auroral latitudes with a longer duration.