Magnetic Energy Conversion and Transport in the Terrestrial Magnetotail Due to Dipolarization Fronts

Abstract

AbstractDipolarization front (DF) is an important region involved with energy conversion and flux transport in the planet's magnetotail. Using observation data from the recent Magnetospheric Multiscale (MMS) mission, we have identified and analyzed 215 DF events. Significant magnetic energy conversion and transport are observed at the DFs, which show strong dawn‐dusk asymmetry. We find that the transport process dominates the change of local magnetic energy. Nearly 70% of the events show net Poynting flux flowing into the DF region. Such effect is more significant than local magnetic energy dissipation, averagely. When DF approaches the near‐Earth region, the net flow‐in Poynting flux decreases and magnetic energy dissipation increases. Our results suggest that the downstream magnetic energies of transient magnetic reconnections in the midtail may be transported to the near‐Earth region by one DF event after another. These intensive strikes to the magnetosphere in the near‐planet region may drive stronger storms, compared with the previous knowledge about DF.