Pc3 pulsations during variable IMF conditions

U. Villante (1) , S. Lepidi (1, 2) , P. Francia (1) , M. Vellante (1) , A. Meloni (2) , R. P. Lepping (3) , F. Mariani (1)

1 Dipartimento di Fisica
2 Istituto Nazionale di Geofisica
3 GSFC Laboratory for Extraterrestrial Physics

Pc3 geomagnetic field fluctuations detected at low latitude (L'Aquila, Italy) during the passage of a high velocity solar wind stream, characterized by variable interplanetary magnetic field conditions, are analyzed. Higher frequency resonant fluctuations and lower frequency phenomena are simultaneously observed; the intermittent appearance and the variable frequency of the longer period modes can be well interpreted in terms of the variable IMF elements; moreover their polarization characteristics are consistent with an origin related to external waves propagating in antisunward direction. A comparison with simultaneous observations performed at Terra Nova Bay (Antarctica) provides additional evidence for a clear relationship between the IMF and Pc3 pulsations also at very high latitudes.

Domaines: Océan, Atmosphère; Sciences de la Terre

U. Villante, S. Lepidi, P. Francia, M. Vellante, A. Meloni, et al.. Pc3 pulsations during variable IMF conditions. Annales Geophysicae, 1999, 17 (4), pp.490-496. ⟨hal-00316569⟩