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arXiv · 0801.2877

Acoustic oscillations in a field-free cavity under solar small-scale bipolar magnetic canopy

D. Kuridze·T. V. Zaqarashvili·B. M. Shergelashvili1·S. Poedts
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Abstract

Observations show the increase of high-frequency wave power near magnetic network cores and active regions in the solar lower atmosphere. This phenomenon can be explained by the interaction of acoustic waves with a magnetic field. We consider small-scale, bipolar, magnetic field canopy structure near the network cores and active regions overlying field-free cylindrical cavities of the photosphere. Solving the plasma equations we get the analytical dispersion relation of acoustic oscillations in the field-free cavity area. We found that the m = 1 mode, where m is azimuthal wave number, cannot be trapped under the canopy due to energy leakage upwards. However, higher ($m \geq 2$) harmonics can be easily trapped leading to the observed acoustic power halos under the canopy.

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D. Kuridze, T. V. Zaqarashvili, B. M. Shergelashvili1, S. Poedts. 2008-01-18. Acoustic oscillations in a field-free cavity under solar small-scale bipolar magnetic canopy. https://doi.org/10.5194/angeo-26-2983-2008

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