HR: 1340h
AN: SM43C-1243    [Abstracts]
TI: Trans-polar Transmission of Pc 3-4 ULF Waves: Results from Cluster and Antarctic Observations
AU: * Pilipenko, V
EM: pilipenk@augsburg.edu
AF: Space Research Institute, Profsojuznaja 84/32, Moscow, 117810 Russian Federation
AU: Chugunova, O
EM: ch.olga@nln.ru
AF: Space Research Institute, Profsojuznaja 84/32, Moscow, 117810 Russian Federation
AU: Engebretson, M
EM: engebret@augsburg.edu
AF: Augsburg College, 2211 Riverside Ave., Minneapolis, MN 55454 United States
AU: Glassmeier, K
EM: kh.glassmeier@tu-bs.de
AF: Institute for Geophysics and Meteorology, Technical University of Braunschweig, Braunschweig, D-38106 Germany
AU: Vellante, M
EM: massimo.vellante@aquila.infn.it
AF: Consorzio Area di Ricerca Astrogeofisica, University of L'Aquila, L'Aquila, 67010 Italy
AU: DeLauretis, M
EM: marcello.delauretis@aquila.infn.it
AF: Consorzio Area di Ricerca Astrogeofisica, University of L'Aquila, L'Aquila, 67010 Italy
AU: Ponomarenko, P
EM: phpp@alinga.newcastle.edu.au
AF: University of Newcastle, Callaghan, Newcastle, NSW 2308 Australia
AB: The possibility of transpolar transmission of Pc3-4 ULF waves is considered using data from search-coil magnetometers from AGOs D5 and D6 in Antarctica, situated on opposite sides of the geomagnetic pole. The diurnal variation of the number of time intervals when Pc3-4 ULF wave activations are simultaneously observed at both stations shows that synchronous ULF activity increases when one of the stations, especially P6, passes local noon. The Cluster satellites have been used, in conjunction with ground observations, to analyze a Pc3-4 wave event in the polar cap. The wave magnetic power was predominantly in the field-aligned component and all components correlated well with small phase delay between all four satellites. Ground-satellite correlations in this frequency range demonstrate that traveling compressional Pc3-4 waves on open field lines are related to the ground wave activity in the polar cap. Additionally, an analysis of a campaign of ULF geomagnetic field measurements during November 2003 at the new Italian/French base Dome C, close to the geomagnetic pole, is presented together with a comparison with simultaneous measurements conducted with similar search-coil magnetometers at McMurdo, Terra Nova Bay, Casey, and South Pole. The variable solar wind conditions allowed to monitor the Pc 3-4 ULF pulsation activity both during quiet period and strong magnetic storm. For quiet magnetospheric conditions, the pulsation power maximizes around local magnetic noon at poleward auroral boundary, but it does not show any evidence for a diurnal modulation in the polar cap. During a strong geomagnetic storm, the wave activity at all stations seem to be driven preferably by strong solar wind pressure pulses. Several Pc3-4 wave events were simultaneously detected in the polar cap and onboard Cluster satellites. These observations indicate the possibility of additional channel of Pc3-4 wave transmission from the upstream region to the ground - via the open field lines at polar latitudes, where mode conversion occurs owing to an unidentified mechanism.
DE: 2475 Polar cap ionosphere
DE: 2706 Cusp
DE: 2752 MHD waves and instabilities (2149, 6050, 7836)
DE: 2776 Polar cap phenomena
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005