Abstract

The eruptive, radiative, and particulate output of the Sun are modulated by our star's enigmatic 11-year sunspot cycle. Over the past year we have identified observational signatures which illustrate the ebb and flow of the 11-year cycle – arising from the temporal overlap of migrating activity b... Show moreThe eruptive, radiative, and particulate output of the Sun are modulated by our star's enigmatic 11-year sunspot cycle. Over the past year we have identified observational signatures which illustrate the ebb and flow of the 11-year cycle – arising from the temporal overlap of migrating activity bands which belong to the 22-year magnetic activity cycle. (At the 2012 Fall Meeting, Leamon & McIntosh presented a prediction of minimum conditions developing in 2017 and Cycle 25 sunspots first appearing in late 2019.) As a consequence of this work we have deduced that the latitudinal interaction of the oppositely signed magnetic activity bands in each hemisphere (and across the equator near solar minimum) dramatically impacts the production of Space Weather events such as flares and Coronal Mass Ejections (CMEs). The same set of observations also permits us to identify a quasi-annual variability in the rotating convecting system which results in a significant local modulation of solar surface magnetism. That modulation, in turn, forces prolonged periods of significantly increased flare and CME production, as well as significant changes in the Sun's ultraviolet (UV), extreme ultraviolet (EUV), and X-Ray irradiance. Show less