MMS statistical analysis of magnetic structures in turbulent magnetotail*

The Earth's magnetotail is a natural laboratory to study turbulent reconnection and their role in particle acceleration. We present a statistical study of over 1000 magnetic structures (MS) measured aboard the Magnetospheric Multiscale (MMS) spacecraft in the magnetotail, selected from regions of large magnetic turbulence and significant particle heating. The MS are detected with an automated algorithm based on previous research [1] using bipolar signatures in the magnetic field, then they are classified into plasmoids, pull current sheet, and push current sheets, typical MS during multiscale reconnection. Many of the MS exhibit magnetic energy dissipation which is dominated by perpendicular electron flow, indicating that they may be inside electron diffusion regions. Change in kinetic energy around MS is dominated by Fermi acceleration which is observed to be largest in plasmoids. There is also a weak correlation between betatron acceleration and perpendicular power law index change. These statistical results represent our continued effort to quantify the process of magnetic energy dissipation in MS and give us a glimpse into the physics of multi-scale turbulent reconnection.