Fig. 3
Magnetic index Sym-H (a), eastward interplanetary electric field Ey (b), ionospheric vertical plasma drift Vd (c), GPS S4 index (d), VHF S4 index (e) and the VHF zonal drift (f) for the days 06 to 10. The light blue shaded area at c represents the prereversal period of 21:00–24:00 UT (18:00–21:00 LT), and the vertical dashed red lines represent the 2 SSCs
