Fig. 16.

Left Fluences of 12–80 MeV/nucleon Fe in large SEP events from solar cycle 23 versus the suprathermal Fe density averaged over the day before the SEP event. The dashed black line is 3333 times the number-density scale. Right Histogram of daily averaged suprathermal Fe densities for all days from March 1998 to December 2005 (left scale) compared to a histogram of suprathermal Fe densities, measured one day before the associated SEP events (right scale). Image reproduced with permission from Mewaldt et al. (2012b), copyright by AIP