Numerical study of MHD wave propagation in the solar atmosphere

SIEYRA, V.; SCHNEITER,M; COSTA, A; ESQUIVEL, A.

Cartagena

Conferencia; XV Latin American Regional IAU Meeting Cartagena; 2018

International Astronomical Union

On July 6, 2011, high spatial resolution images of the solar corona recorded in the extreme ultraviolet (EUV) channels of the Atmospheric Imaging Assembly (AIA) instrument onboard the Solar Dynamics Observatory (SDO) detected a recurrent, arc-shaped emission over a sunspot in NOAA AR 1243. The emission fronts propagated along a coronal loop bundle rooted in a small area of the dark umbra. No flaring or coronal mass ejection was associated with this phenomenon. Preliminary analysis suggests that the fronts propagate with an average phase velocity of ~50 km/sec, exhibit a periodicity ~3 minutes, and appear to be rooted in an umbral dot. In this work, we investigate (1) the nature of these quasi-periodic fronts that look like ?bubbles? (i.e., are they bubbles or are they signatures of magnetosonic waves?), and (2) the driver of this recurrent phenomenon. To shed light into the physical nature of these ?bubbles? we run a 2D MHD simulation based on a potential field extrapolation of the sunspot magnetic field in a gravitationally stratified atmosphere. The sunspot magnetic field is obtained from line-of-sight magnetograms provided by the Helioseismic and Magnetic Imager (HMI) instrument onboard SDO. Here we report on the kinematical properties and frequency characterization of the event, and describe the details of the simulation along with some early outcomes from initial tests.