Reply to Comment on “Unraveling the Causes of Radiation Belt Enhancements”

Numerous current systems contribute to the magnetic perturbations used to calculate the Dst index. Ionospheric and field‐aligned current effects are minimized, although not always well [e.g., Friedrich et al. , 1999], by averaging measurements from a worldwide chain of low‐latitude stations. The index is imperfect, but it has been shown that Biot‐Savart magnetic perturbations from magnetospheric currents derived from in situ particle observations can account for most of the Dst variation [ Greenspan and Hamilton , 2000; Turner et al. , 2001; Jorgenson et al. , 2004].