Three‐dimensional MHD Model of Wave Activity in a Coronal Active Region

Abstract

MHD wave activity associated with a flare was observed in coronal activeregion AR 8270 in the extreme ultraviolet (EUV) by the Transition Regionand Coronal Explorer (TRACE) satellite on 1998 July 14. In this study, athree-dimensional MHD model of the active region field was initializedusing a National Solar Observatory (NSO) Kitt Peak magnetogram andpotential extrapolation of the magnetic field, together withgravitationally stratified density. To model the observed wave activityfollowing the flare, a velocity pulse was launched into a model activeregion from below. It was found that the global oscillations in themodel active region are in good qualitative agreement with observations.The main difference between the observations and the model is in theoscillation of several individual loops that damp on longer timescalescompared to the corresponding magnetic field line oscillation damping inthe model.