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| Titel |
Photospheric high-frequency acoustic power excess in sunspot umbra: signature of magneto-acoustic modes |
| VerfasserIn |
S. Zharkov, S. Shelyag, V. Fedun, R. Erdélyi, M. J. Thompson |
| 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. 8 ; Nr. 31, no. 8 (2013-08-06), S.1357-1364 |
| Datensatznummer |
250086089
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| Publikation (Nr.) |
 copernicus.org/angeo-31-1357-2013.pdf |
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| Zusammenfassung |
| We present observational evidence for the presence of MHD (magnetohydrodynamic) waves in the solar
photosphere deduced from SOHO/MDI (Solar and Heliospheric Observatory/Michelson Doppler Imager) Dopplergram velocity observations.
The magneto-acoustic perturbations are observed as acoustic power
enhancement in the sunspot umbra at high-frequency bands in the velocity component
perpendicular to the magnetic field.
We use numerical modelling of wave propagation through localised non-uniform
magnetic field concentration along with the same filtering procedure as applied to the observations
to identify the observed waves.
Guided by the results of the numerical simulations we
classify the observed oscillations as magneto-acoustic waves excited by the
trapped sub-photospheric acoustic waves.
We consider the potential application of the presented method
as a diagnostic tool for magnetohelioseismology. |
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