Coronal Inflows and the Sun’s Nonaxisymmetric Open Flux

Abstract

Wang et al. recently described white-light coronagraph observations of faint coronal features moving inward toward the Sun at heliocentric distances of 2-6 R☉. In a study of these inflows during 1996-2000, we have found that they occur along bends of the coronal streamer belt and are especially common when the magnetic field has a four-sector structure. The measured inflow rate is dominated by episodic bursts that are correlated with the occurrence of nonpolar coronal holes and other indicators of the Sun's nonaxisymmetric open flux. However, the inflow rate has only a broad long-term correlation with conventional indicators of solar activity like the sunspot number and coronal mass ejection rate. We conclude that most inflows indicate collapsing field lines that occur as nonpolar coronal holes are subjected to photospheric motions and the eruptions of new flux.