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Ion Scattering and Energization in Filamentary Structures Through Earth's Magnetosheath
Author(s) -
Chaston C. C.,
Travnicek P.
Publication year - 2021
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2021gl094029
Subject(s) - magnetosheath , physics , magnetopause , magnetosphere , ion , scattering , computational physics , adiabatic process , anisotropy , plasma , pitch angle , geophysics , atomic physics , optics , quantum mechanics
Multi‐point measurements on kinetic scales through Earth's magnetosheath have revealed a spectrum of filamentary currents and vortical flows advected with the shocked plasmas outside the magnetopause. The spectral energy density in these structures is correlated with enhanced ion temperatures. Using an empirically derived statistical model based on fluid‐kinetic theory for these structures we demonstrate how they act to scatter magnetosheath ions. Through the combined action of energization in the direction perpendicular to the background magnetic field along chaotic orbits, and pitch‐angle scattering into the parallel direction appreciable ion energization occurs. These dynamics drive heating while generating non‐thermal energetic tails similar to that observed. It is shown how the operation of this process depends on the field topology with deviations from planar form and counter‐propagation required to drive significant energization. This process will modulate ion anisotropies through the magnetosheath independent of both adiabatic effects and the action of anisotropy instabilities.