Signatures of heavy ion reconnection in the magnetotail: simulations and satellite observations

Reconnection plays an important role in magnetospheric dynamics, but most studies of reconnection are limited to plasmas with only 2 species: electrons and ions. During active periods, however, the number density of oxygen atoms in the magnetotail can exceed that of the protons. Recent work has shown that if the density of oxygen atoms is high enough, the reconnection dissipation region becomes more complicated, becoming mediated by the "heavy whistler" at the heavy ion inertial length. An important question to examine is how large the oxygen density must be to see signatures associated with the heavy whistler. In this study, we will present 3-species reconnection simulations with appropriate parameters for the magnetotail at active times. The focus is on gaining an understanding of how the signatures of heavy ion reconnection are modified as the heavy ion density changes. In addition, we will present CLUSTER observations of magnetotail reconnection in the presence of oxygen.