Ripoll J., M. Denton, V. Loridan, O. Santol{‘{i}}k, D. Malaspina, D. P. 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. Kletzing, J. Wygant, M. G. Henderson, A. Y. Ukhorskiy, (2020), How whistler mode hiss waves and the plasmasphere drive the quiet decay of radiation belts electrons following a geomagnetic storm, Journal Of Physics: Conference Series, 1623, 012005, doi:10.1088/1742-6596/1623/1/012005

## 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 plasma 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 freshly injected electrons into the atmosphere 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 variations in the trapped electron population with time, space, energy, and pitch angle that is based on the 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 equatorial pitch angle α 0∼100 keV, 3.5## Authors (sorted by name)

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

Journal Of Physics: Conference Series## Bibtex

@article{Ripoll_2020,
doi = {10.1088/1742-6596/1623/1/012005},
url = {https://doi.org/10.1088/1742-6596/1623/1/012005},
year = 2020,
month = {sep},
publisher = {{IOP} Publishing},
volume = {1623},
pages = {012005},
author = {J-F Ripoll and M Denton and V Loridan and O Santol{'{i}}k and D Malaspina and D P 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 Kletzing 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},
journal = {Journal of Physics: Conference Series},
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 plasma 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 freshly injected electrons into the atmosphere 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 variations in the trapped electron population with time, space, energy, and pitch angle that is based on the 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 equatorial pitch angle α 0∼100 keV, 3.5}}