Oscillation characteristics of Pi 2 in auroral zone: Syowa-Iceland conjugate study

Oscillation characteristics of Pi 2 magnetic pulsations observed in auroral region have been statistically examined on the basis of the magnetic field data obtained at the conjugate stations, Syowa Station in Antarctica and Husafell, Isafjordur and Tjornes in Iceland. The examination reveals that the characteristics are quite different between the H and D components of Pi 2 magnetic pulsations. The pulsations in H component show larger amplitude than in the D component. The orientation of the principal axis, ellipticity and phase relations of Pi 2 oscillations are also statistically investigated. The important characteristics of Pi 2 as hydromagnetic waves (HM waves) generated in the magnetosphere are believed to be exhibited well in the H component. All of the characteristics show that oscillations of Pi 2 in auroral region are found to be resonant oscillations of magnetic field-line. Regarding the conjugacy of Pi 2 oscillations, Syowa and Husafell is also found to be the best conjugate station-pair in comparison with other station-pairs of Syowa-Isafjordur, and Syowa-Tjornes