Woodfield E. E., S. A. Glauert, J. D. Menietti, T. F. Averkamp, R. B. Horne, Y. Y. Shprits, (2019), Rapid Electron Acceleration in Low-Density Regions of Saturn’s Radiation Belt by Whistler Mode Chorus Waves, Geophysical Research Letters, 46, 7191-7198, doi:10.1029/2019GL083071

## Abstract

Abstract Electron acceleration at Saturn due to whistler mode chorus waves has previously been assumed to be ineffective; new data closer to the planet show it can be very rapid (factor of 104 flux increase at 1 MeV in 10 days compared to factor of 2). A full survey of chorus waves at Saturn is combined with an improved plasma density model to show that where the plasma frequency falls below the gyrofrequency additional strong resonances are observed favoring electron acceleration. This results in strong chorus acceleration between approximately 2.5 RS and 5.5 RS outside which adiabatic transport may dominate. Strong pitch angle dependence results in butterfly pitch angle distributions that flatten over a few days at 100s keV, tens of days at MeV energies which may explain observations of butterfly distributions of MeV electrons near L=3. Including cross terms in the simulations increases the tendency toward butterfly distributions.## Authors (sorted by name)

Averkamp Glauert Horne Menietti Shprits Woodfield## Journal / Conference

Geophysical Research Letters## Bibtex

@article{10.1029/2019GL083071,
author = {Woodfield, E. E. and Glauert, S. A. and Menietti, J. D. and Averkamp, T. F. and Horne, R. B. and Shprits, Y. Y.},
title = {Rapid Electron Acceleration in Low-Density Regions of Saturn's Radiation Belt by Whistler Mode Chorus Waves},
journal = {Geophysical Research Letters},
volume = {46},
number = {13},
pages = {7191-7198},
keywords = {Saturn, radiation belt, electron, wave-particle interaction, whistler mode chorus waves},
doi = {https://doi.org/10.1029/2019GL083071},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL083071},
eprint = {https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2019GL083071},
abstract = {Abstract Electron acceleration at Saturn due to whistler mode chorus waves has previously been assumed to be ineffective; new data closer to the planet show it can be very rapid (factor of 104 flux increase at 1 MeV in 10 days compared to factor of 2). A full survey of chorus waves at Saturn is combined with an improved plasma density model to show that where the plasma frequency falls below the gyrofrequency additional strong resonances are observed favoring electron acceleration. This results in strong chorus acceleration between approximately 2.5 RS and 5.5 RS outside which adiabatic transport may dominate. Strong pitch angle dependence results in butterfly pitch angle distributions that flatten over a few days at 100s keV, tens of days at MeV energies which may explain observations of butterfly distributions of MeV electrons near L=3. Including cross terms in the simulations increases the tendency toward butterfly distributions.},
year = {2019}
}