Memoirs of the Kakioka Magnetic Observatory Vol.20 No.01， p.1, March, 1983
Wave Characteristics of Magnetic Pi2 Pulsations in the Magnetosphere and on the Ground
The Pi2 wave characteristics are studied by using ULF data simultaneously obtained at the geosynchronous satellite, ATS6, and at the conjugate ground-based stations (Syowa Station in Antarctica and Reykjavik in Iceland). It is experimentally clarified that the major axis of the Pi2 wave polarization is rotated through 90° in a propagation from the magnetosphere to the ground through the ionosphere. The evidence indicates that Pi2 is caused by the fundamental-mode of the hydro-magnetic torsional oscillation of the localized field lines anchored on the night-side auroral ovals. The amplitude behavior of Pi2 also supports the standing oscillation of the field lines as a cause of Pi2.