Speaker
Description
Magnetohydrodynamic (MHD) waves are ubiquitous in the solar atmosphere and are key in many models for seismological or energy conversion processes. Coronagraphs such as Metis on board Solar Orbiter have already detected wave-like disturbances and other such instruments on board Aditya-L1 and PROBA-3 are likely to follow observing them at unprecedented spatial and temporal resolutions, opening pathways to study MHD waves in the outer corona. Such white light images are crucial to understand wave properties which are manifested as density variations, as the wave motions and the background solar wind displace the local plasma. Using 2.5-D MHD modelling, we study these waves in the solar atmosphere as they evolve along open and closed magnetic field structures such as coronal holes and helmet streamers as far as up to ~20 solar radii, also carried by a background solar wind that transitions from being sub-Alfvénic to super-Alfvénic. Our model takes into account spherical expansion, gravitational stratification, thermal conduction, and radiative cooling, and provides indications on the detectability of such waves, observed as density variations by Metis and the new-generation coronagraphs from different vantage points.
