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Model of lifetimes of the outer radiation belt electrons in a realistic magnetic field using realistic chorus wave parameters

Orlova K., Y. Shprits, (2014), Model of lifetimes of the outer radiation belt electrons in a realistic magnetic field using realistic chorus wave parameters, J. of Geophys. Res. [Space Physics], 119, 770-780, doi:10.1002/2013JA019596

Abstract

Abstract The outer radiation belt electrons in the inner magnetosphere show high variability during the geomagnetically disturbed conditions. Quasi-linear diffusion theory provides both a framework for global prediction of particle loss at different energies and an understanding of the dynamics of different particle populations. It has been recently shown that the pitch angle scattering of electrons due to wave-particle interaction with chorus waves modeled in a realistic magnetic field may be significantly different from those estimated in a dipole model. In this work, we present the lifetimes of 1 keV–2 MeV electrons computed in the Tsyganenko 89 magnetic field model for the night, dawn, prenoon, and postnoon magnetic local time (MLT) sectors for different levels of geomagnetic activity and distances. The lifetimes in the realistic field are also compared to those computed in the dipole model. We develop a realistic chorus lower band and upper band wave models for each MLT sector using the recent statistical studies of wave amplitude, wave normal angle, and wave spectral density distributions as functions of magnetic latitude, distance, and Kp index. The increase of plasma trough density with increasing latitude is also included. The obtained in the Tsyganenko 89 field electron lifetimes are parameterized and can be used in 2-D/3-D/4-D convection and particle tracing codes.

Authors (sorted by name)

Orlova Shprits

Journal / Conference

Journal Of Geophysical Research (Space Physics)

Acknowledgments

We thank D. Subbotin and A. Drozdov for useful discussions and M. Spasojevic for discussions on providing chorus waves amplitudes at low latitudes. The authors are also grateful to the developers of IRBEM library. The research of K. Orlova was supported by the NASA Living with a Star Jack Eddy Postdoctoral Fellowship Program, administered by the University Corporation for Atmospheric Research. The work of Y. Shprits was supported by a Presidential Early Career Award for Scientists and Engineers (PECASE) award grant. This research was also supported by the UC‐Lab Fee program, NASA grants NNX10AK99G, NNX09AF51G, NNX13AE34G, and NSF AGS‐1203747.

Grants

AGS‐1203747 NNX09AF51G NNX10AK99G NNX13AE34G PECASE

Bibtex

@article{doi:10.1002/2013JA019596,
author = {Orlova, Ksenia and Shprits, Yuri},
title = {Model of lifetimes of the outer radiation belt electrons in a realistic magnetic field using realistic chorus wave parameters},
journal = {Journal of Geophysical Research: Space Physics},
volume = {119},
number = {2},
pages = {770-780},
year={2014},
keywords = {electron lifetimes, wave-particle interaction, chorus waves, non-dipole field, pitch-angle diffusion, radiation belts},
doi = {10.1002/2013JA019596},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2013JA019596},
eprint = {https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2013JA019596},
abstract = {Abstract The outer radiation belt electrons in the inner magnetosphere show high variability during the geomagnetically disturbed conditions. Quasi-linear diffusion theory provides both a framework for global prediction of particle loss at different energies and an understanding of the dynamics of different particle populations. It has been recently shown that the pitch angle scattering of electrons due to wave-particle interaction with chorus waves modeled in a realistic magnetic field may be significantly different from those estimated in a dipole model. In this work, we present the lifetimes of 1 keV–2 MeV electrons computed in the Tsyganenko 89 magnetic field model for the night, dawn, prenoon, and postnoon magnetic local time (MLT) sectors for different levels of geomagnetic activity and distances. The lifetimes in the realistic field are also compared to those computed in the dipole model. We develop a realistic chorus lower band and upper band wave models for each MLT sector using the recent statistical studies of wave amplitude, wave normal angle, and wave spectral density distributions as functions of magnetic latitude, distance, and Kp index. The increase of plasma trough density with increasing latitude is also included. The obtained in the Tsyganenko 89 field electron lifetimes are parameterized and can be used in 2-D/3-D/4-D convection and particle tracing codes.}
}