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| Titel |
Mapping of the quasi-periodic oscillations at the flank magnetopause into the ionosphere |
| VerfasserIn |
E. R. Dougal, K. Nykyri, T. W. Moore |
| 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. 11 ; Nr. 31, no. 11 (2013-11-18), S.1993-2011 |
| Datensatznummer |
250086146
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| Publikation (Nr.) |
 copernicus.org/angeo-31-1993-2013.pdf |
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| Zusammenfassung |
| We have estimated the ionospheric location, area, and travel time of
quasi-periodic oscillations originating from the magnetospheric flanks. This
was accomplished by utilizing global and local MHD models and Tsyganenko
semi-empirical magnetic field model on multiple published and four new cases believed to
be caused by the Kelvin–Helmholtz Instability. Finally, we used auroral,
magnetometer, and radar instruments to observe the ionospheric signatures. The
ionospheric magnetic latitude determined using global MHD and Tsyganenko models
ranged from 58.3–80.2 degrees in the Northern Hemisphere and −59.6 degrees to
−83.4 degrees in the Southern Hemisphere. The ionospheric magnetic local time
ranged between 5.0–13.8 h in the Northern Hemisphere and 1.3–11.9 h
in the Southern Hemisphere. Typical Alfvén wave travel time from spacecraft
location to the closest ionosphere ranged between 0.6–3.6 min. The
projected ionospheric size calculated at an altitude of 100 km ranged from 47–606 km,
the same order of magnitude as previously determined ionospheric
signature sizes. Stationary and traveling convection vortices were observed in
SuperDARN radar data in both hemispheres. The vortices were between 1000–1800 km
in size. Some events were located within the ionospheric footprint
ranges. Pc5 magnetic oscillations were observed in SuperMAG magnetometer data
in both hemispheres. The oscillations had periods between 4–10 min with
amplitudes of 3–25 nT. They were located within the ionospheric footprint
ranges. Some ground magnetometer data power spectral density peaked at
frequencies within one tenth of a mHz of the peaks found in the corresponding
Cluster data. These magnetometer observations were consistent with previously published
results. |
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