Nature of axial tail instability and bubble-blob formation in near-Earth plasma sheet

摘要: [1] Previous global magnetohydrodynamic (MHD) simulations of substorm events have identified the dynamic presence an axial tail instability that is uniform in dawn-dusk direction near-Earth plasma sheet. The found to be a major cause initial growing MHD force imbalance on closed field lines prior subsequent magnetic reconnection and expansion onset processes. In this work, energy principle analysis indicates two-dimensional thin current sheet configuration magnetotail typically stable mode within framework ideal model. However, linear resistive calculations find instabilities generalized Harris configurations. properties these are similar modes observed simulations. unstable regimes low Lundquist number regions with small normal component field. Such would by many researchers considered as tearing configuration. Unlike conventional sheet, does not involve any process. Instead, nature dominantly slippage process among neighboring flux tubes facilitated dissipation. A natural consequence shown formation bubble-blob pairs pressure entropy profiles