Local Cutoff Frequencies for Transverse Waves Propagating Along Thin and Non-Isothermal Magnetic Flux Tubes
Abstract
Propagation of transverse waves along thin magnetic flux tubes embedded in an isothermal atmosphere is affected by the cutoff frequency, which is a global quantity that restricts the wave propagation to only those frequencies that are higher than the cutoff. Since the solar atmosphere is not isothermal, the effects of different temperature gradients on the cutoff are investigated. A method to determine these effects is presented and applied to specific models of solar magnetic flux tubes. An interesting result is that the resulting cutoff frequency is a local quantity in the model, and that its value at a given height determines the frequency that transverse tube waves must have in order to be propagating at this height. The obtained results are applied to the solar atmospheric oscillations.
- Publication:
-
European Solar Physics Meeting
- Pub Date:
- September 2008
- Bibcode:
- 2008ESPM...12.3.25M