Ripoll J., M. Denton, V. Loridan, O. Santolik, D. Malaspina, D. Hartley, G. S. Cunningham, G. Reeves, S. Thaller, D. L. Turner, J. F. Fennell, A. Y. Drozdov, J. S. Cervantes Villa, Y. Y. Shprits, X. Chu, G. Hospodarsky, W. S. Kurth, C. A. Kletzin, J. Wygant, M. G. Henderson, A. Y. Ukhorskiy, (2019), How whistler mode hiss waves and the plasmasphere drive the quiet decay of radiation belts electrons following a geomagnetic storm, Astronum

## Abstract

We show how an extended period of quiet solar wind conditions contributes to a quiet state of the plasmasphere that expands up to L ~ 5.5, which creates the perfect conditions for wave-particle interactions between the radiation belt electrons and whistler mode hiss waves. The correlation between the hiss waves and the density is direct with hiss wave power increasing with plasma density, while it was generally assumed that these quantities can be specified independently. Whistler mode hiss waves pitch angle diffuse and ultimately scatter in the atmosphere the electrons brought by the storm until the slot region is formed between the inner and outer belt and the outer belt is drastically reduced. In this study, we use and combine Van Allen Probes observations and Fokker-Planck numerical simulations. The Fokker-Planck model uses consistent event-driven pitch angle diffusion coefficients from whistler mode hiss waves. Observations and simulations allow us to reach a global understanding of the trapped electrons variation with time, space, energy, and pitch angle that is based on existing theory of quasi-linear wave-particle interactions. We show, for instance, the outer belt is pitch-angle homogeneous, which is explained by the event-driven diffusion coefficients that are roughly constant for α0~100 keV, 3.5## Authors (sorted by name)

Cervantes Villa Chu Cunningham Denton Drozdov Fennell Hartley Henderson Hospodarsky Kletzin Kurth Loridan Malaspina Reeves Ripoll Santolik Shprits Thaller Turner Ukhorskiy Wygant## Journal / Conference

2019-ASTRONUM## Bibtex

@inproceeding{Ripoll-2019-as,
author = {J-F Ripoll and M Denton and V Loridan and O Santolik and D Malaspina and D Hartley and G S Cunningham and G Reeves and S Thaller and D L Turner and J F Fennell and A Y Drozdov and J S {Cervantes Villa} and Y Y Shprits and X Chu and G Hospodarsky and W S Kurth and C A Kletzin and J Wygant and M G Henderson and A Y Ukhorskiy},
title = {How whistler mode hiss waves and the plasmasphere drive the quiet decay of radiation belts electrons following a geomagnetic storm},
booktitle = {ASTRONUM},
year = {2019},
series = {Paris, France},
editor = {},
volume = {},
series = {},
pages = {},
note = {June, 2019},
abstract = {We show how an extended period of quiet solar wind conditions contributes to a
quiet state of the plasmasphere that expands up to L ~ 5.5, which creates the perfect conditions
for wave-particle interactions between the radiation belt electrons and whistler mode hiss
waves. The correlation between the hiss waves and the density is direct with hiss wave power
increasing with plasma density, while it was generally assumed that these quantities can be
specified independently. Whistler mode hiss waves pitch angle diffuse and ultimately scatter in
the atmosphere the electrons brought by the storm until the slot region is formed between the
inner and outer belt and the outer belt is drastically reduced. In this study, we use and combine
Van Allen Probes observations and Fokker-Planck numerical simulations. The Fokker-Planck
model uses consistent event-driven pitch angle diffusion coefficients from whistler mode hiss
waves. Observations and simulations allow us to reach a global understanding of the trapped
electrons variation with time, space, energy, and pitch angle that is based on existing theory of
quasi-linear wave-particle interactions. We show, for instance, the outer belt is pitch-angle
homogeneous, which is explained by the event-driven diffusion coefficients that are roughly
constant for α0~100 keV, 3.5}
}