Home » Uzbekov et al. 2016

Scattering of Relativistic and Ultra-relativistic Electrons by Obliquely Propagating Electromagnetic Ion Cyclotron Waves

Uzbekov B., Y. Shprits, K. Orlova, (2016), Scattering of Relativistic and Ultra-relativistic Electrons by Obliquely Propagating Electromagnetic Ion Cyclotron Waves, Journal Of Atmospheric And Solar-terrestrial Physics, 148, 22-31, doi:10.1016/j.jastp.2016.08.004

Abstract

Electromagnetic Ion Cyclotron (EMIC) waves are transverse plasma waves that are generated in the Earth magnetosphere by ring current protons with temperature anisotropy in three different bands: below the , and ion gyrofrequencies. EMIC events are enhanced during the main phase of a geomagnetic storm when intensifications in the electric field result in enhanced injections of ions and are usually confined to high-density regions just inside the plasmapause or within drainage plumes. EMIC waves are capable of scattering radiation belt electrons and thus provide an important link between the intensification of the electric field, ion populations, and radiation belt electrons. Bounce-averaged diffusion coefficients computed with the assumption of parallel wave propagation are compared to the results of the code that uses the full cold plasma dispersion relation taking into account oblique propagation of waves and higher-order resonances. We study the sensitivity of the scattering rates to a number of included higher-order resonances, wave spectral distribution parameters, wave normal angle distribution parameters, ambient plasma density, and ion composition. Inaccuracies associated with the neglect of higher-order resonances and oblique propagation of waves are compared to potential errors introduced by uncertainties in the model input parameters.

Authors (sorted by name)

Orlova Shprits Uzbekov

Journal / Conference

Journal Of Atmospheric And Solar-terrestrial Physics

Acknowledgments

We would like to thank Lynn Kistler, Matina Gkioulidou, Maria Usanova, Adam Kellerman and Alexander Drozdov for their contribution and advice. Support at UCLA was provided by NASA grant NNX10AK99GNNX13AE34GNSF grant 443869-YS-21686, and UC Lab Feegrant #116720Horizon 2020 #637302. We would like to thank International Space Science Institute (Bern) for the support provided.

Grants

116720 443869-YS-21686 637302 NNX10AK99G NNX13AE34G

Bibtex

@article{doi:10.1016/j.jastp.2016.08.004,
author = {Uzbekov, B. and Shprits, Y. and Orlova, K.},
title = {Scattering of Relativistic and Ultra-relativistic Electrons by Obliquely Propagating Electromagnetic Ion Cyclotron Waves},
year = {2016},
journal = { Journal of Atmospheric and Solar-Terrestrial Physics},
volume = {148},
pages = {22-31},
doi = {10.1016/j.jastp.2016.08.004},
url = {https://doi.org/10.1016/j.jastp.2016.08.004},
abstract = {Electromagnetic Ion Cyclotron (EMIC) waves are transverse plasma waves that are generated in the Earth magnetosphere by ring current protons with temperature anisotropy in three different bands: below the ,  and  ion gyrofrequencies. EMIC events are enhanced during the main phase of a geomagnetic storm when intensifications in the electric field result in enhanced injections of ions and are usually confined to high-density regions just inside the plasmapause or within drainage plumes. EMIC waves are capable of scattering radiation belt electrons and thus provide an important link between the intensification of the electric field, ion populations, and radiation belt electrons. Bounce-averaged diffusion coefficients computed with the assumption of parallel wave propagation are compared to the results of the code that uses the full cold plasma dispersion relation taking into account oblique propagation of waves and higher-order resonances. We study the sensitivity of the scattering rates to a number of included higher-order resonances, wave spectral distribution parameters, wave normal angle distribution parameters, ambient plasma density, and ion composition. Inaccuracies associated with the neglect of higher-order resonances and oblique propagation of waves are compared to potential errors introduced by uncertainties in the model input parameters.}
}