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| Titel |
Identification of slow magnetosonic wave trains and their evolution in 3-D compressible turbulence simulation |
| VerfasserIn |
L. Zhang, L.-P. Yang, J.-S. He, C.-Y. Tu, L.-H. Wang, E. Marsch, X.-S. Feng |
| 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 (2015-01-07), S.13-23 |
| Datensatznummer |
250121143
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| Publikation (Nr.) |
 copernicus.org/angeo-33-13-2015.pdf |
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| Zusammenfassung |
| In solar wind, dissipation of slow-mode magnetosonic waves
may play a significant role in heating the solar wind, and these modes
contribute essentially to the solar wind compressible turbulence.
Most previous identifications of slow waves utilized the characteristic negative
correlation between δ|B| and δρ.
However, that criterion does not well identify quasi-parallel slow waves,
for which δ|B| is negligible compared to
δρ.
Here we present a new method of identification, which will be
used in 3-D compressible simulation. It is based on two criteria:
(1) that VpB0 (phase speed projected along B0)
is around ± cs, and that
(2) there exists a clear correlation of δv|| and δρ.
Our research demonstrates that if vA > cs,
slow waves possess correlation between δv|| and δρ,
with δρ / δv|| ≈ ± ρ0 / cs.
This method helps us to distinguish slow-mode waves from fast and Alfvén
waves, both of which do not have this polarity relation.
The criteria are insensitive to the propagation angle
θk B, defined as the angle between wave
vector k and B0;
they can be applied with a wide range of β if only
vA > cs.
In our numerical simulation, we have identified four cases of slow wave
trains with this method.
The slow wave trains seem to deform, probably caused by
interaction with other waves; as a result, fast or Alfvén waves
may be produced during the interaction and seem to propagate
bidirectionally away.
Our identification and analysis of the wave trains
provide useful methods for investigations of compressible
turbulence in the solar wind or in similar environments,
and will thus deepen understandings of slow waves in the turbulence. |
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