Fig. 3

MMS field and particle observations during dipolarization. Energy spectra from a electrons and b ions obtained from the EIS and FPI instruments. Electron spectra for energy lower/higher than 25 keV are plotted using FPI and EIS data. Ion spectra for energy higher/lower than 45/30 keV are plotted using EIS/FPI data. c V, d D, and e H components of the magnetic fields from the four MMS spacecraft. f P parallel (black) and perpendicular (red) components of the currents determined using the curlometer method and parallel current calculated using FPI ion and electron moments (blue curve). g V, h D, and i H components of the plasma flows perpendicular to the magnetic field and E × B drifts. The blue curves in g–i correspond to E × B drift obtained from EDP, whereas the red curves are the ion velocity from FPI, and the black curves show the proton velocity from HPCA. j V, D, and H components of the electric fields. The vertical dashed lines show the start of the crossing times of the main current layers associated with the dipolarization: (i) 10:01:22, (ii) 10:01:43, (iii) 10:02:4, and 1 (iv) 10:03:01. The horizontal black bars in g–i present the timing velocity. This velocity is determined from the time delays between the four spacecraft in the B _D traces during the time interval represented, and is indicated by the lengths of the horizontal bars. The four bottom panels (k–n) show the average ion flows perpendicular to the magnetic field (green) and electric field (dark blue) during the four current sheet crossings (i–iv). The magnetic field disturbance vector (difference between the end and the start time of the crossing) is shown in black, and the timing velocity vector is in red