Observational and numerical characterization of a wave-like front propagating along pseudo-open field lines above an active region

SIEYRA, V; STENBORG, G; COSTA, A.; ESQUIVEL, A. Y CÉCERE, M.

San Juan

Congreso; Towards Future Research on Space Weather Drivers; 2019

Early on the day, 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 intensity disturbance over a sunspot in NOAA AR 1243. The intensity fronts were observed to propagate along a coronal loop bundle rooted in a small area of the dark umbra of the sunspot. Neither signatures of flare activity nor of a coronal mass ejection event were observed in association with the phenomenon. A preliminary analysis suggests that the fronts 1) propagate with a projected, average phase velocity of about 50 km/sec, the exact value depending upon the EUV channel analyzed; 2) exhibit a pseudo-periodic recurrence with a period of about 3 minutes; and 3) appear to be rooted in an umbral dot. To shed light into the physical nature of the event, we performed numerical simulations based on a simple potential magnetic field configuration embedded in a gravitationally stratified atmosphere. In this presentation, we 1) report on the kinematical properties and frequency characterization of the event as observed at the different temperature regimes covered by the SDO/AIA images, and 2) compare them with the results from the numerical simulations carried out. In brief, the analysis suggests that the wave-like, recurrent fronts are a signature of a slow-mode magneto-sonic wave.