Fig. 1: Snapshots zooming to the tail current sheet.
From: Magnetotail plasma eruptions driven by magnetic reconnection and kinetic instabilities
a–g, The panels are given in the Geocentric Solar Ecliptic coordinate system, where X points sunwards, the Y axis is in the ecliptic plane and positive towards the dusk and the Z axis completes the system and is positive northwards. The shown plasma sheet surface is given by the condition Br = 0, where Br is the radial magnetic field B component. Snapshots are given at 1,300 s (a), 1,350 s (b), 1,400 s (c), 1,428 s (d), 1,443 s (e), 1,450 s (f) and 1,470 s (g) (see the whole sequence in Supplementary Video 1). Colour gives the current density J. The thick yellow contour shows the plasma flow reversal (V'x = 0) between the Earthward and tailward flow regions, after subtracting the tailward lobe velocity (see Methods, ‘Applicability’). Magenta and green contours are neutral line proxies where Br = 0 and Bz = 0. The derivative of Bz is used as a proxy to classify the neutral line as x and o topologies, such that the radial gradient ∂Bz /∂r is negative (green) and positive (magenta), respectively, at o and x topologies. On top of the o-topology green contours, part of the magnetic-field lines are additionally depicted with green thin lines to further illustrate the o topology. The dominant reconnection line is assumed to exist where the magenta (∂Bz/∂r > 0) and yellow contours are approximately co-located, while those locations where only the magenta line exists are either local reconnection or, for example, dipolarization fronts29. The background grid shows the coordinates but also the magnetic-field topology: the black grid shows areas where the magnetic field is northwards, and the white grid shows the areas where it is southwards. The arrows are referred to in the text. The dashed magenta lines in d indicate the locations of the cuts at fixed X and Y coordinates, presented in Fig. 2.
