  We present first results derived from the largest collection of
contemporaneously recorded Jovian sodium nebula and Io plasma torus (IPT) in [S
II] 673.1 nm images assembled to date. The data were recorded by the Planetary
Science Institute's Io Input/Output observatory (IoIO) and provide important
context to Io geologic and atmospheric studies as well as the Juno mission and
supporting observations. Enhancements in the observed emission are common,
typically lasting 1 -- 3 months, such that the average flux of material from Io
is determined by the enhancements, not any quiescent state. The enhancements
are not seen at periodicities associated with modulation in solar insolation of
Io's surface, thus physical process(es) other than insolation-driven
sublimation must ultimately drive the bulk of Io's atmospheric escape. We
suggest that geologic activity, likely involving volcanic plumes, drives
escape.
