8-12 July 2013
Africa/Johannesburg timezone
<a href="http://events.saip.org.za/internalPage.py?pageId=13&confId=32"><font color=#ff0000>SAIP2013 PROCEEDINGS AVAILABLE</font></a>

Acoustic resonators above sunspot umbrae

10 Jul 2013, 14:50
20m
Oral Presentation Track D2 - Space Science Space Science

Speaker

Dr G.J.J. Botha (Northumbria University)

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

Yes

Abstract content <br> &nbsp; (Max 300 words)

The three-minute oscillations in the chromosphere above sunspot umbrae are explained by means of an acoustic resonator. In the vertical magnetic field above umbrae a cavity forms between the photosphere and transition region that acts as a leaky resonator, where the oscillations generate traveling waves that propagate upward into the solar corona. One-dimensional numerical simulations using the ideal magnetohydrodynamic equations demonstrate the existence of the resonator. The shapes and peaks in the resonating spectrum raise the possibility of using the resonator as a means to determine the chromospheric temperature profile above umbrae. A numerical study will be presented of different initiators of the oscillations, as well as the influence of the shape and height of the chromospheric cavity.

Apply to be<br> considered for a student <br> &nbsp; award (Yes / No)?

No

Primary author

Dr G.J.J. Botha (Northumbria University)

Co-authors

Prof. T.D. Arber (Warwick University) Prof. V.M. Nakariakov (Warwick University)

Presentation Materials

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