A case study of a radially polarized Pc4 event observed by the Equator-S satellite
oleh: R. Cramm, R. Cramm, R. Cramm, K. H. Glassmeier, K. H. Glassmeier, K. H. Glassmeier, C. Othmer, C. Othmer, C. Othmer, K. H. Fornacon, K. H. Fornacon, K. H. Fornacon, H. U. Auster, H. U. Auster, H. U. Auster, W. Baumjohann, W. Baumjohann, W. Baumjohann, E. Georgescu, E. Georgescu, E. Georgescu, E. Georgescu
| Format: | Article |
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| Diterbitkan: | Copernicus Publications 2000-04-01 |
Deskripsi
A 16 mHz Pc4 pulsation was recorded on March 17, 1998, in the prenoon sector of the Earth's magnetosphere by the Equator-S satellite. The event is strongly localized in radial direction at approximately <i>L</i> = 5 and exhibits properties of a field line resonance such as an ellipticity change as seen by applying the method of the analytical signal to the magnetic field data. The azimuthal wave number was estimated as <i>m</i> \approx 150. We discuss whether this event can be explained by the FLR mechanism and find out that the change in ellipticity is more a general feature of a localized Alfvén wave than indicative of a resonant process.<br><br><b>Key words:</b> Magnetospheric physics (MHD waves and instabilities)