[PEM14-P20] Observation of auroral brightenings and fast plasma flows produced by magnetic reconnection in the magnetotail
Keywords:aurora, substorm, magnetic reconnection
At 06-07 UT February 27, 2009, each of THEMIS satellites were located near midnight 21 Re (THEMIS-1), 18 Re (THEMIS-2) and 11 Re (THEMIS-3, 4, 5) down the tail. Satellite foot-points were located near Gillam (magnetic latitude: 66.0 degree) in Canada. An auroral brightening started at 0636:00 UT (23.5 MLT) with ray structure. At this time, THEMIS-1 observed tailward fast flow at 21 Re. In addition, THEMIS-3, 4 observed earthward fast flow at 11Re. In contrast, THEMIS-2 did not observed fast flow. Since the plasma beta was decreasing at this time, THEMIS-2 moved toward the tail lobe. These THEMIS 2 observations suggest that no fast flow was observed at 18 Re because the plasma sheet was thinning.