Fig. 5
From: Geomagnetic storms of cycle 24 and their solar sources
Scatter plots of the 1-h averaged solar wind speed (V) and the north–south component of solar wind magnetic field (Bz). The left panel is for the rising–maximum phases of cycle 23 (1996–2002), and the right panel is for cycle 24 (2009–2015). The dotted curves show E d–d of ±5, ±10, ±15, and ±20 mV/m, respectively