Correlation between continuous lobe reconnection in the mid magnetotail and substorm expansion onset
Glassmeier, K. -H.; Dunlop, M. W.; Reme, H.; Korth, A.; Zhang, Hui; Friedel, R.; Reeves, G. D.; Pu, Zuyin; Cao, Xin; Fu, Suiyan; Xiao, Chijie; Liu, Zhenxing; Frazen, M.; Zong, Quiging
China, Germany, United States, France, United Kingdom
Abstract
Data on plasma sheet crossing measured by Cluster/HIA and Cluster/FGM during the period from July to October in 2001-2003 are analyzed. Based on previous work on the characteristic features of continuous lobe reconnection (CLR) described in reference, two case studies and a statistical analysis were carried out on correlation between CLR in the mid magnetotail and substorm expansion onset for the events occurring during this period. It is found that almost all CLR events are in close connection with substorms. The beginning of CLR is almost always a few minutes ahead of substorm activities seen in the near Earth magnetotail and on the ground-based stations. This provides a clear indication that CLR is the virtual cause of substorm expansion onset during the period of continuous southward interplanetary magnetic field.