Turbulent energy conversion associated with kinetic microinstabilities in Earth's magnetosheath
Author(s)
Type
Journal Article
Abstract
Plasma in Earth's magnetosheath rarely experiences interparticle collisions, so kinetic microinstabilities are thought to contribute to regulating the plasma thermodynamics. Instabilities excite waves and redistribute free energy in velocity space, reducing free energy in the velocity distribution function (VDF). Using 24 hr of data spread over 163 intervals of in situ magnetosheath observations by Magnetospheric Multiscale (MMS), we investigate signatures of energy conversion where the turbulent dynamics have locally distorted the VDFs into non-Maxwellian shapes, in the context of electron and ion temperature anisotropy driven instabilities. We find enhanced average energy conversion into the particles along instability boundaries, suggesting turbulence plays a role in redistributing free energy. In so doing, we quantify the energetics associated with unstable conditions for both species. This work provides insight into the open question of how specific plasma processes couple into the turbulent dynamics, ultimately leading to energy dissipation and particle energization in collisionless plasmas.
Date Issued
2024-12-28
Date Acceptance
2024-11-18
Citation
Geophysical Research Letters, 2024, 51 (24)
ISSN
0094-8276
Publisher
Wiley
Journal / Book Title
Geophysical Research Letters
Volume
51
Issue
24
Copyright Statement
© 2024. The Author(s). This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Subjects
ANISOTROPY
ELECTRON FIREHOSE INSTABILITY
FIELD
Geology
Geosciences, Multidisciplinary
heliosphere
HELIOSPHERE
kinetic microinstabilities
MAGNETIC RECONNECTION
magnetosheath
Physical Sciences
plasma instabilities
Science & Technology
space plasma physics
SPECTRA
turbulence
WHISTLER
Publication Status
Published
Article Number
e2024GL112038
Date Publish Online
2024-12-16