Electron Physics in 3‐D Two‐Fluid 10‐Moment Modeling of Ganymede's Magnetosphere
Open Access
- 23 March 2018
- journal article
- research article
- Published by Wiley in Journal of Geophysical Research: Space Physics
- Vol. 123 (4) , 2815-2830
Abstract
We studied the role of electron physics in 3‐D two‐fluid 10‐moment simulation of Ganymede's magnetosphere. The model captures nonideal physics like the Hall effect, electron inertia, and anisotropic, nongyrotropic pressure effects. A series of analyses were carried out: (1) The resulting magnetic field topology and electron and ion convection patterns were investigated. The magnetic fields were shown to agree reasonably well with in situ measurements by the Galileo satellite. (2) The physics of collisionless magnetic reconnection were carefully examined in terms of the current sheet formation and decomposition of generalized Ohm's law. The importance of pressure anisotropy and nongyrotropy in supporting the reconnection electric field is confirmed. (3) We compared surface “brightness” morphology, represented by surface electron and ion pressure contours, with oxygen emission observed by the Hubble Space Telescope. The correlation between the observed emission morphology and spatial variability in electron/ion pressure was demonstrated. Potential extension to multi‐ion species in the context of Ganymede and other magnetospheric systems is also discussed.Keywords
All Related Versions
Funding Information
- National Aeronautics and Space Administration (NNX13AK31G)
- U.S. Department of Energy (DESC0006670)
- University Corporation for Atmospheric Research (AGS-1338944)
- National Natural Science Foundation of China
This publication has 40 references indexed in Scilit:
- The role of ion cyclotron motion at Ganymede: Magnetic field morphology and magnetospheric dynamicsGeophysical Research Letters, 2006
- Resistive MHD simulations of Ganymede's magnetosphere 2. Birkeland currents and particle energeticsJournal of Geophysical Research, 2002
- Resistive MHD simulations of Ganymede's magnetosphere 1. Time variabilities of the magnetic field topologyJournal of Geophysical Research, 2002
- Collisionless reconnection supported by nongyrotropic pressure effects in hybrid and particle simulationsJournal of Geophysical Research, 2001
- Geospace Environmental Modeling (GEM) Magnetic Reconnection ChallengeJournal of Geophysical Research, 2001
- Collisionless reconnection: Effects of Hall current and electron pressure gradientJournal of Geophysical Research, 2000
- Sudden enhancement and partial disruption of thin current sheets in the magnetotail due to Hall MHD effectsGeophysical Research Letters, 1998
- The magnetic field and magnetosphere of GanymedeGeophysical Research Letters, 1997
- Evidence for a magnetosphere at Ganymede from plasma-wave observations by the Galileo spacecraftNature, 1996
- Theoretical models of magnetic field line mergingReviews of Geophysics, 1975