References

ANGEO

Annales Geophysicae

ANGEO

Ann. Geophys.

1432-0576

Copernicus Publications

Göttingen, Germany

10.5194/angeo-25-2045-2007

Daily variation at Concordia station (Antarctica) and its dependence on IMF conditions

Cafarella

¹ Di Mauro

¹ Lepidi

¹ Meloni

¹ Pietrolungo

¹ Santarelli

¹ Schott

J. J.

Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy

Ecole et Observatoire des Science de la Terre, IPG, Strasbourg, France

02 10 2007

25 9 2045 2051

2007

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After some short test surveys, during the 2004–2005 summer expedition in Antarctica, a geomagnetic French-Italian observatory was installed on the plateau (geographic coordinates: 75.1° S, 123.4° E; corrected geomagnetic coordinates: 88.9° S, 54.3° E; UT=LT−8) very close to the geomagnetic pole. In this paper we present some peculiarities of the daily variation as observed at this polar cap observatory during the years 2005 and 2006, taking into account 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 analysis showed that different Bz conditions correspond to different 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.

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