ORIGIN AND EVOLUTION OF CORONAL STREAMER STRUCTURE DURING THE 1996 MINIMUM ACTIVITY PHASE

We employ coronal extrapolations of solar magnetograph data to interpr et observations of the white-light streamer structure made with the LA SCO coronagraph in 1996. The topological appearance of the streamer be lt during the present minimum activity phase is well described by a mo del in which the Thomson-scattering electrons are concentrated around a single, warped current sheet encircling the Sun. Projection effects give rise to bright, jet-like structures or spikes whenever the curren t sheet is viewed edge-on; multiple spikes are seen if the current she et is sufficiently wavy. The extreme narrowness of these features in p olarized images indicates that the scattering layer is at most a few d egrees wide. We model the evolution of the streamer belt from 1996 Apr il to 1996 September and show that the effect of photospheric activity on the streamer belt topology depends not just on the strength of the erupted magnetic flux, but also on its longitudinal phase relative to the background field. Using flux transport simulations, we also demon strate how the streamer belt would evolve during a prolonged absence o f activity.