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| Titel |
Global characteristics of Pc1 magnetic pulsations during solar cycle 23 deduced from CHAMP data |
| VerfasserIn |
J. Park, H. Lühr, J. Rauberg |
| 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 ; 31, no. 9 ; Nr. 31, no. 9 (2013-09-05), S.1507-1520 |
| Datensatznummer |
250086102
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| Publikation (Nr.) |
 copernicus.org/angeo-31-1507-2013.pdf |
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| Zusammenfassung |
| We present a global climatology of Pc1 pulsations as observed by the CHAMP
satellite from 2000 to 2010. The Pc1 center frequency and bandwidth are about
1 and 0.5 Hz, respectively. The ellipticity is mostly linear with the
major axis almost aligned with the magnetic zonal direction. The diurnal
variation of Pc1 occurrences shows a primary maximum early in the morning and
a secondary maximum during pre-midnight hours. The annual variations of the
occurrence rates exhibit a clear preference for local summer. The solar cycle
dependence of the occurrence rate reveals a maximum at the declining phase
(2004–2005). Neither magnetic activity nor solar wind velocity controls the
Pc1 occurrence rate significantly. Pc1 occurrence rate peaks at subauroral
latitudes, but the steep cutoff towards higher latitudes is due to auroral
field-aligned currents masking the Pc1 pulsations. The center frequency of
Pc1 pulsations does not show a clear dependence on latitude. The global
distribution of Pc1 exhibits highest occurrence rates near the longitude
sector of the South Atlantic Anomaly. Pc1 events at auroral latitudes,
although they are rarely detected, show a clear occurrence peak around local
noon. A majority of the auroral Pc1 events are observed during solar minimum
years. |
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