Search process illustration. Top panel: magnetic field’s amplitude for the first encounter (B_tot), as well as a 2-h running median (in blue) and r the radial distance to the Sun. Bottom panel: relative variation of B_tot regarding its 2h running median, with emphasis on over +30% relative variation. The gray arrow in the top panel indicates the event occurring on November 2, 2018, which is detailed in Sect. 3.