Continuous lobe reconnection in the mid-tail and its relationship to substorms: Cluster observations of continuous lobe reconnection in the mid-magneto tail

摘要

When the IMF turns southward, a great amount of magnetic energy is stored In the magnetotail, and the electric field across the magnetotail substantially enhances. As long as magnetic reconnection (MR) in the magnetotail initiates and continues, the magnetic field and plasma in the central plasma sheet are carried away to the near-Earth and down to the tail, the magnetic field and plasma in the lobe region enter the CPS and are involved in MR. We call this process "Continuous Lobe Reconnection (CLR)". In this paper a detailed analysis of Cluster observation of MR through 2001-2003 is made. Plenty of CLR events are found that led to considerable changes of tail configuration, appearance of BBF, as well as large-scale bubbles in which both plasma temperature and number density substantially decrease. It is shown that in general CLR events last for dozens of minutes and have good correspondence to substorm initiation under the condition of continuous southward IMF.