Pc3 pulsations during variable IMF conditions

• Main Authors: U. Villante, S. Lepidi, P. Francia, M. Vellante, A. Meloni, F. Mariani
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Terra Nova Bay; Antarc*; Antarctica
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.371.8915; http://hal.archives-ouvertes.fr/docs/00/31/65/69/PDF/angeo-17-490-1999.pdf

Abstract. Pc3 geomagnetic ®eld ¯uctuations detected at low latitude (L'Aquila, Italy) during the passage of a high velocity solar wind stream, characterized by variable interplanetary magnetic ®eld conditions, are analyzed. Higher frequency resonant ¯uctuations 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. Key words. Magnetospheric physics (MHD waves and instabilities; solar wind ± magnetosphere interactions)