Wave‐driven gradual loss of energetic electrons in the slot region

Resonant pitch angle scattering by plasmaspheric hiss has long been considered to be responsible for the energetic electron loss in the slot region, but the detailed quantitative comparison between theory and observations is still lacking. Here we focus on the loss of 100–600 keV electrons at L = 3 during the recovery phase of a geomagnetic storm on 28 June 2013. Van Allen Probes data showed the concurrence of intense (with power up to 10−4 nT2/Hz) plasmaspheric hiss waves and significant (up to 1 order) loss of energetic electrons within 2 days. Our quasi‐linear diffusion simulations show that hiss scattering can basically reproduce the temporal evolution of the angular distribution of the observed electron flux decay. This quantitative analysis provides further support for the mechanism of hiss‐driven electron loss in the slot region. Key Points We focus on the loss of 100‐600 keV electrons in the slot region (L = 3) during the recovery phase of a geomagnetic storm on 28 June 2013 Van Allen Probes data showed the concurrence of intense plasmaspheric hiss waves and significant loss of energetic electrons within 2 days Our quasi‐linear diffusion simulations including the hiss waves can basically reproduce the observed electron flux decay