Virtues of Including Hydrogen in the Patterns of Element Abundances in Solar Energetic Particles

We revisit a multi-spacecraft study of the element abundances of solar energetic particles (SEPs) in the 23 January 2012 event, where the power-law pattern of enhancements versus the mass-to-charge ratio A/Q for the elements C through Fe was partly disrupted by a break near Mg, which turned out to be an unfortunate distraction. In the current article we find that extending that least-squares fits for C - Fe down to H at A/Q = 1 lends much more credence to the power laws, even though H itself was not included in the fits. We also investigate the extent of an adiabatically invariant "reservoir" of magnetically-trapped particles behind the shock wave in this event.