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| Titel |
Three-dimensional multi-fluid model of a coronal streamer belt with a tilted magnetic dipole |
| VerfasserIn |
L. Ofman, E. Provornikova, L. Abbo, S. Giordano |
| 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 ; 33, no. 1 ; Nr. 33, no. 1 (2015-01-12), S.47-53 |
| Datensatznummer |
250121147
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| Publikation (Nr.) |
 copernicus.org/angeo-33-47-2015.pdf |
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| Zusammenfassung |
| Observations of streamers in extreme ultraviolet (EUV) emission with SOHO/UVCS show dramatic
differences in line profiles and latitudinal variations in heavy ion
emission compared to hydrogen Ly-α emission. In order to use ion
emission observations of streamers as the diagnostics of the slow solar wind
properties, an adequate model of a streamer including heavy ions is required.
We extended a previous 2.5-D multi-species magnetohydrodynamics (MHD) model of a coronal streamer to
3-D spherical geometry, and in the first approach we consider a tilted dipole
configuration of the solar magnetic field. The aim of the present study is to
test the 3-D results by comparing to previous 2.5-D model result for a 3-D
case with moderate departure from azimuthal symmetry. The model includes
O5+ ions with preferential empirical heating and allows for calculation
of their density, velocity and temperature in coronal streamers. We present the
first results of our 3-D multi-fluid model showing the parameters of protons,
electrons and heavy ions (O5+) at the steady-state solar corona with a
tilted steamer belt. We find that the 3-D results are in qualitative
agreement with our previous 2.5-D model, and show longitudinal variation in
the variables in accordance with the tilted streamer belt structure.
Properties of heavy coronal ions obtained from the 3-D model together with
EUV spectroscopic observations of streamers will help understanding the 3-D
structures of streamers reducing line-of-sight integration ambiguities and
identifying the sources of the slow solar wind in the lower corona. This leads to improved understanding of the physics of the slow solar wind. |
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