Analysis of energy conversion processes at kinetic scales associated with a series of dipolarization fronts observed by MMS during a substorm

In July 2017, the MMS constellation was in the magnetotail with an apogee of 25 Earth radiiand an average inter-satellite distance of 10 km (i.e. at electron scales). On 23 July around16:19 UT, MMS was located at the edge of the current sheet which was in a quasi-staticstate. Then, MMS suddenly entered in the central plasma sheet and detected the local onsetof a small substorm as indicated by the AE index (~400 nT). Fast earthward plasma flowswere measured for about 1 hour starting with a period of quasi-steady flow and followed bya saw-tooth like series of fast flows associated with dipolarization fronts. This plasmatransport sequence finished with a flow reversal still occurring close to the magneticequator. In the present study, we investigate the energy conversion processes at ion andelectron scales for these different phases with particular attention on the processes in thevicinity of the dipolarization fronts.