(A) Positions of MMS2 (red), MMS3 (green), and MMS4 (blue) relative to MMS1 (black) in the L–N (left panel) and M–N (right panel) planes at 21:27:30 UT on 2017 November 12. The red arrow indicates the solar wind direction. The gray dashed lines are parallel to the solar wind flow. (B) Schematic of the geometry of the magnetic hole in the M–N plane. The color bar indicates the magnetic field strength. MMS2/3 and 4 have been shifted to MMS1 along the solar wind flow in the M–N plane as shown by the red arrow. The horizontal lines from right to left indicate BT observed by the satellites with time. The orange arrows indicate the strength and direction of the electron velocities inside the magnetic hole in the M–N plane. The radius of the gray circle is 6 ρe.