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| Titel |
Location of Pc 1–2 waves relative to the magnetopause |
| VerfasserIn |
R. E. Denton, J. LaBelle, X. Zhu |
| 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 ; 20, no. 11 ; Nr. 20, no. 11, S.1763-1767 |
| Datensatznummer |
250014491
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| Publikation (Nr.) |
 copernicus.org/angeo-20-1763-2002.pdf |
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| Zusammenfassung |
Spacecraft-borne and
ground-based magnetometers frequently detect magnetospheric micropulsations in
the period range 0.2–10 s, termed Pc 1–2, and attributed to electromagnetic
ion cyclotron waves driven by temperature anisotropy (T^
> T ||). Previous surveys of
Pc 1 occurrence locations have been limited to L < 9. We
present AMPTE/IRM observations of the distribution of Pc 1 waves out to the
magnetopause, for a limited region of MLT = 10–14. The probability of wave
occurrence Pwav is large (> 0.15) between L = 7–12,
peaking at L = 8–10 (Pwav ~ 0.25). When the L-value
is normalized to the magnetopause position Lmp, however, the
highest probabilities of Pc 1 wave occurrence are close to the magnetopause,
with Pwav ~0.25 for Lnorm = L/Lmp
= 0.8–1.0. These results are consistent with increased convective growth rate
at large L and with the greater effect of magnetosphere compression
close to the magnetopause. On the other hand, we only directly observe magnetic
field compression for at most about 25% of the wave events.
Key words. Magnetospheric physics (magnetospheric
configuration and dynamics; MHD waves and instabilities; plasma waves and
instabilities) |
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