Bibliography

We provide a comprehensive statistical analysis of the sample entropy of peak and time-integrated geomagnetic events in 2001\textendash2017, considering different measures of event strength, different geomagnetic indices, and a simplified solar wind-magnetosphere coupling function . Our investigations reveal the existence of significant correlations between the entropies of , , and , and between such entropies and event strengths, as well as good correlations between peak levels of solar wind-magnetosphere coupling and ring current ( ) and entropies, suggesting a potential predictability of significant and events on the basis of appropriate functions of . Sensibly weaker correlations are found with entropy. We further show the presence of several significant entropy correlations between geomagnetic indices, solar wind-magnetosphere coupling, and trapped or precipitated energetic electron and ion fluxes measured by geostationary and low Earth orbit satellites in the outer radiation belt during the same periods. Entropy correlations between and trapped or precipitated 30- to 80-keV ion fluxes at low and between and trapped 40-keV electron fluxes at geostationary orbit correspond well with ring current properties and substorm-induced injections, respectively. Entropy correlations between and precipitation rates of energetic ion and electron fluxes demonstrate the sensibility of index entropy to both low-energy (5\textendash30 keV) electron injections and ring current. The stronger entropy correlation between solar wind-magnetosphere coupling and than likely stems from the more stochastic behavior of electron injections and fast losses near geostationary orbit.