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| Titel |
SIGNATURES OF TWO DISTINCT INITIATION MECHANISMS WHILE CMEs EVOLVE IN THE LOWER CORONA |
| VerfasserIn |
M. V. Alves, C. L. de Souza Costa, M. Opher, Y. C. Liu, W. B. Manchester, T. I. Gombosi |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250029033
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| Zusammenfassung |
| We present a comparison of a three-dimensional (3D) simulation of coronal mass ejections
(CMEs) formed with two different initiation mechanisms: Gibson & Low (1998) (as GL98
from now on) and Titov & Démoulin (1999) (as TD99 from now on). Mainly we aim to
compare how the CME magnetic configuration changes during their propagation in the lower
corona, until 6RS. The simulations are performed using the Space Weather Modeling
Framework (SWMF) during the solar minimum (CR1922). We found that both CME-driven
shocks are quasi-parallel at the nose and that GL98 presents a higher shock acceleration
(~150 m/ s2versus ~100 m/ s2) and a higher Mach number, suggesting it would
accelerate particles more efficiently. Both initiation mechanisms also presented a
post-shock compression for R>3RS, being slightly larger in TD99. They presented
also a similar sheath width that increases while propagating away from the Sun
(larger in GL98 case). We also found that in GL98 case the CME is driven by a
combination of magnetic and thermal pressure, while in TD99 case the thermal pressure
dominates its evolution. GL98 presents a sheath mass 20% larger than TD99, a possible
explanation for the presence of higher force values for GL98. This paper intends to
serve as a prototype for future comparisons of CME evolution, in the lower corona. |
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