Observational Interpretation of an Active Prominence on 1999 May 1

Abstract

This paper presents an observational study of an active prominence observed in He I 1083 nm intensity and velocity data obtained at the Mauna Loa Solar Observatory, which provide physical insight into dynamical processes associated with prominences. We compare these observations with existing theoretical prominence models, which fall into two main classes : dip models and Ñux rope models. Dip models use sagging magnetic arches to explain prominence support, while Ñux rope models are characterized by helical magnetic Ðeld lines that trap prominence material at the bottom of the rope. The prominence on which we focus in the present paper has four interesting components of activity, all of which we attempt to explain using each of three di †erent prominence models : the normal and inverse polarity Ñux rope models and the dip model. Our objective is to test the viability of each of these models in describing this type of activity. The model that appears consistent with the observed activity in this particular prominence is the inverse polarity Ñux rope model. We suggest that the process of vertical reconnection between an inverse polarity Ñux rope and an underlying magnetic arcade may best describe the observed prominence activity.