It is well-known that there are many wave-particle interaction processes which have the potential to affect the dynamics of the radiation belts [see e.g., the review by Mauk et al., 2013]. The issue that has continued to obstruct significant advances in our understanding of the radiation belts to the point of predictability is our ability to represent the nature of the magnetospheric processes controlling belt dynamics with sufficient accuracy to establish which dominate. In relation to the case examined here it is to determine which process or processes can act to create a third Van Allen radiation belt morphology in September 2012 as reported by Baker et al., (2013). As described in the main text of our Reply, and further expanded upon in the Supplementary Material presented here, we show that the original conclusion from Mann et al. (2016) remains valid. That is, a remnant belt and the third radiation belt morphology which arises following a subsequent flux recovery at higher L-shells, can be explained by the action of very fast outwards ULF wave radial diffusion associated with magnetopause shadowing. Contrary to the claims of the Comment by Shprits et al. (2017; hereafter S17), and the conclusions of modelling by Shprits et al. (2013; hereafter S13), the action of EMIC waves is not required.
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