The ScienceMedia Network

#### Simulation of a spherical magneto-acoustic wave propagating in the solar atmosphere: interaction with magnetic canopy, $\delta B$

Author: Christian Nutto
Affiliation: Kiepenheuer-Institut für Sonnenphysik, Freiburg, Germany

Main category: Natural Sciences (Astronomy)

Caption:
The spherical magneto-acoustic wave is excited right beneath the magnetic canopy. The color map shows the magnetic field perturbations $\delta B$. The fast magnetic mode in the low regime is supported by magnetic forces, causing signi cant perturbations of the magnetic field.The green contours display the equipartition level, where $c_\mathrm{s} =c_\mathrm{A}$.

Further information:
Since the wave source is located in a region of high plasma- $\beta$, the excited waves are
primarily acoustic in nature. Upon reaching the equipartition level, indicated by the solid
green contour, energy can be exchanged between the two modes of the magnetoacoustic
waves (Schunker and Cally, 2006; Cally, 2007). Due to the large attack angle of
the local wave front with respect to the magnetic field at the location of the equipartition
level, a large fraction of the acoustic wave energy is converted into the fast magnetic mode

Further Reading: Dissertation: Numerical experiments on the propagation of waves in a convectively unstable magneto-atmosphere: A new interpretation of the measured reduction of wave travel-times in magnetic regions of the Sun. (Figure 5.3)