Whistlers in the Plasmasphere

Author
Keywords
Abstract
Abstract We study packages of VLF whistler-mode waves observed by the Van Allen Probes satellites in the equatorial plasmasphere. We demonstrate that the main mechanism providing localization of these waves inside relatively broad (>1 RE across the ambient magnetic field) magnetospheric regions is a combined effect of the transverse gradients in the plasma density and the ambient magnetic field. The criterion for the wave trapping by these gradients is the same as for the wave trapping inside a high-density duct with a symmetric, Gaussian-like profile of the density in the uniform magnetic field. This criterion can be used to determine the parallel wavelength of the wave with a known frequency trapped by the density and magnetic field inhomogeneities with known parameters. The developed theoretical approach demonstrates a good, quantitative agreement with the observations. The analytical results have been confirmed with comprehensive, time-dependent simulations of the electron-MHD model.
Notes
Year of Publication
2021
Journal
Journal of Geophysical Research: Space Physics
Volume
126
Number
Number of Pages
e2020JA028933
Date Published
02/2021
URL
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020JA028933
DOI
https://doi.org/10.1029/2020JA028933