Energy release and transport in the near-Earth magnetotail associated with substorms: THEMIS observations

Our previous statistical studies showed that the total pressure decreases in the magnetic reconnection region at X ~ -18 Re and its surrounding regions, associated with substorm expansion onsets, while it increases in the initial dipolarization region earthward of X ~ -12 Re. It was also found that the total pressure decrease, i.e., energy release is more significant between the regions of the magnetic reconnection and the initial dipolarization than in the magnetic reconnection region. In the present study, we investigate the total pressure decrease between the magnetic reconnection and initial dipolarization regions for a few individual events observed by the THEMIS spacecraft. The preliminary analysis shows that during the pressure decrease, wave activity, and electron and ion energization were seen, regardless of fast earthward flows, although these activities were stronger in case of fast flows. We discuss energy release and transport as well as the relationship between fast flow, wave activity, and particle energization.