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    | Titel | Observation of low frequency electromagnetic activity at 1000 km altitude |  
    | VerfasserIn | N. Ivchenko, G. Marklund |  
    | Medientyp | Artikel 
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    | Sprache | Englisch 
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    | ISSN | 0992-7689 
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    | Digitales Dokument | URL |  
    | Erschienen | In: Annales Geophysicae ; 19, no. 6 ; Nr. 19, no. 6, S.643-648 |  
    | Datensatznummer | 250014276 
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    | Publikation (Nr.) |  copernicus.org/angeo-19-643-2001.pdf |  
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        | Zusammenfassung |  
        | We present a statistical
 study of low frequency fluctuations of electric and magnetic fields, commonly
 interpreted as Alfvénic activity. The data base consists of six months of
 electric and magnetic field measurements by the Astrid-2 microsatellite. The
 occurrence of the events is studied with respect to the location and general
 activity. Large regions of broadband Alfvénic activity are persistently
 observed in the cusp/cleft and, during the periods of high geo-magnetic
 activity, also in the pre-midnight sector of the auroral oval. 
 Key words. Ionosphere (auroral
 ionosphere) – Space plasma physics (waves and instabilities) –
 Magnetospheric physics (magnetosphere-ionosphere interactions)
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