A statistical analysis of low-frequency magnetic pulsations at cusp and cap latitudes in Antarctica

• Published in: Journal of Geophysical Research
• Main Authors: Francia, P., Lanzerotti, L. J., Villante, U., Lepidi, S., Di Memmo, D.
• Other Authors: Francia, P.; Università dell'Aquila, Italia, Lanzerotti, L. J.; New Jersey Institute of Technology, NJ, USA, Villante, U.; Università dell'Aquila, Italia, Lepidi, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia, Di Memmo, D.; Università dell'Aquila, Italia, Università dell'Aquila, Italia, New Jersey Institute of Technology, NJ, USA, Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2005
• Subjects: geomagnetic pulsations; magnetospheric dynamics; 01. Atmosphere::01.03. Magnetosphere::01.03.03. Magnetospheric physics; South Pole; Terra Nova Bay; Antarc*; Antarctica; South pole
• Online Access: http://hdl.handle.net/2122/9779; https://doi.org/10.1029/2004JA010680

We report a statistical analysis of low-frequency magnetic variations (magnetic pulsations, 0.8–7 mHz) at South Pole (74 S corrected geomagnetic latitude) and Terra Nova Bay (80 S) during 1996. The results show that at South Pole (at cusp latitudes) the pulsation power exhibits two maxima during the day, one in the local premidnight and the other in the morning. The first maximum disappears when the analysis is restricted to northward interplanetary magnetic field conditions (Bz > 1 nT), suggesting that it might be associated to substorm phenomena. During closed magnetospheric conditions, when the cusp is expected to be located poleward with respect to the station, the spectral and polarization characteristics of pulsations between 1 and 3 mHz suggest that resonant oscillations of the outermost closed field lines commonly occur at South Pole in the local morning. At Terra Nova Bay, in the polar cap, the pulsation power is much lower and its diurnal variation is characterized by a single maximum, which occurs around local noon, when the station approaches the cusp. The corresponding polarization pattern indicates that Terra Nova Bay is always located poleward with respect to resonant field lines. Published A02205 1A. Geomagnetismo e Paleomagnetismo JCR Journal restricted