Electron Kinetic Entropy across Quasi-Perpendicular Shocks
Published in Entropy, 2022
Recommended citation: M. Lindberg, A. Vaivads, S. Raptis, P. Lindqvist, B. L. Giles, D. J. Gershman. (2022). Electron Kinetic Entropy across Quasi-Perpendicular Shocks. Entropy. https://doi.org/10.3390/e24060745
Abstract
We use Magnetospheric Multiscale (MMS) data to study electron kinetic entropy per particle Se across Earth’s quasi-perpendicular bow shock. We have selected 22 shock crossings covering a wide range of shock conditions. Measured distribution functions are calibrated and corrected for spacecraft potential, secondary electron contamination, lack of measurements at the lowest energies and electron density measurements based on plasma frequency measurements. All crossings display an increase in electron kinetic entropy across the shock ΔSe being positive or zero within their error margin. There is a strong dependence of ΔSe on the change in electron temperature, ΔTe, and the upstream electron plasma beta, βe. Shocks with large ΔTe have large ΔSe. Shocks with smaller βe are associated with larger ΔSe. We use the values of ΔSe, ΔTe and density change Δne to determine the effective adiabatic index of electrons for each shock crossing. The average effective adiabatic index is ⟨γe⟩=1.64±0.07.
BibTeX
@article{lindberg2022,
title = {Electron Kinetic Entropy across Quasi-Perpendicular Shocks},
author = {M. Lindberg, A. Vaivads, S. Raptis, P. Lindqvist, B. L. Giles, D. J. Gershman},
journal = {Entropy},
year = {2022},
doi = {10.3390/e24060745}
}