www.ann-geophys.net/25/2045/2007/ © European Geosciences Union 2007

• Main Authors: Its Dependence, L. Cafarella, D. Di Mauro, S. Lepidi, A. Meloni, M. Pietrolungo, L. Santarelli, J. J. Schott
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: cap phenomena; Solar; Antarc*; Antarctica; Geomagnetic Pole
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.592.6130; http://hal.archives-ouvertes.fr/docs/00/33/01/46/PDF/angeo-25-2045-2007.pdf

Abstract. After some short test surveys, during the 2004–2005 summer expedition in Antarctica, a geomagnetic French-Italian observatory was installed on the plateau (ge-ographic coordinates: 75.1 ◦ S, 123.4 ◦ E; corrected geomag-netic coordinates: 88.9 ◦ S, 54.3 ◦ E; UT=LT−8) very close to the geomagnetic pole. In this paper we present some pecu-liarities of the daily variation as observed at this polar cap observatory during the years 2005 and 2006, taking into ac-count the different Loyd seasons and different interplanetary magnetic field conditions. Some interesting results emerge from the analysis, confirming the dependence of the daily variation (and of the associated polar current systems) on the IMF Bz and By components. In particular the analy-sis showed that different Bz conditions correspond to differ-ent contribution to daily variation of ionospheric and field aligned currents, while particular By conditions lead to a time shift of the diurnal variation, indicating an asymmetry with respect to the noon meridian.