Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2011-08-23
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
Accepted for publication in Astronomy & Astrophysics
Scientific paper
MHD wave propagation inside the Sun's atmosphere is closely related to the magnetic field topology. For example, magnetic fields are able to lower the cutoff frequency for acoustic waves thus allowing waves which would otherwise be trapped below the photosphere to propagate into the upper atmosphere. Another example is that MHD waves can be transmitted or converted into other forms of waves at altitudes where the sound speed equals the Alfv\'en speed. We take advantage of the large field-of-view provided by the IBIS experiment to study the wave propagation at two heights in the solar atmosphere, as sampled by the photospheric Fe 617.3 nm spectral line and the chromospheric Ca 854.2 nm spectral line, and its relationship to the local magnetic field. Among other things, we find substantial leakage of waves with 5-minute periods in the chromosphere at the edges of a pore and in the diffused magnetic field surrounding it. By using spectro-polarimetric inversions of Hinode SOT/SP data, we also find a relationship between the photospheric power spectrum and the magnetic field inclination angle; in particular, well-defined transmission peaks around 25\degree for 5 minutes waves and around 15\degree for 3 minutes waves. We propose a very simple model based upon wave transmission theory to explain this behavior. Finally, an analysis of both the power spectra and chromospheric amplification spectra suggests the presence of longitudinal acoustic waves along the magnetic field lines.
Berrilli Francesco
Del Moro Dario
Jefferies Stuart M.
Stangalini Marco
No associations
LandOfFree
MHD wave transmission in the Sun's atmosphere does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with MHD wave transmission in the Sun's atmosphere, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and MHD wave transmission in the Sun's atmosphere will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-67271