Correlations Between Dispersive Alfvén Wave Activity, Electron Energization, and Ion Outflow in the Inner Magnetosphere

Author
Keywords
Abstract
Using measurements from the Van Allen Probes, we show that field-aligned fluxes of electrons energized by dispersive Alfvén waves (DAWs) are prominent in the inner magnetosphere during active conditions. These electrons have preferentially field-aligned anisotropies from 1.2 to >2 at energies ranging from tens of electron volts to several kiloelectron volts (keV), with largest values being coincident with magnetic field dipolarizations. Comparisons reveal that DAW energy densities and Poynting fluxes are strongly correlated with precipitating electron energies and energy fluxes and also O+ ion outflow energies. These observations yield empirical inner magnetosphere relations between the DAW and electron inputs and the O+ ion outflow response, providing important constraints for models. They also suggest that DAWs play an important role in enhancing field-aligned electron input into the ionosphere that facilitates the outflow and subsequent energization of O+ ions in the wave fields into the inner magnetosphere.
Notes
Year of Publication
2020
Journal
Geophysical Research Letters
Volume
47
Number
Number of Pages
e2020GL088985
Date Published
08/2020
URL
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL088985
DOI
https://doi.org/10.1029/2020GL088985