Magnetohydrodynamic Turbulence in the Earth’s Magnetotail From Observations and Global MHD Simulations
| dc.contributor.author | El-Alaoui, Mostafa | |
| dc.contributor.author | Walker, Raymond J. | |
| dc.contributor.author | Weygand, James M. | |
| dc.contributor.author | Lapenta, Giovanni | |
| dc.contributor.author | Goldstein, Melvyn | |
| dc.date.accessioned | 2022-08-24T20:43:44Z | |
| dc.date.available | 2022-08-24T20:43:44Z | |
| dc.date.issued | 2021-03-22 | |
| dc.description.abstract | Magnetohydrodynamic (MHD) turbulent flows are found in the solar wind, the magnetosheath and the magnetotail plasma sheet. In this paper, we review both observational and theoretical evidence for turbulent flow in the magnetotail. MHD simulations of the global magnetosphere for southward interplanetary magnetic field (IMF) exhibit nested vortices in the earthward outflow from magnetic reconnection that are consistent with turbulence. Similar simulations for northward IMF also exhibit enhanced vorticity consistent with turbulence. These result from Kelvin-Helmholtz (KH) instabilities. However, the turbulent flows association with reconnection fill much of the magnetotail while the turbulent flows associated with the KH instability are limited to a smaller region near the magnetopause. Analyzing turbulent flows in the magnetotail is difficult because of the limited extent of the tail and because the flows there are usually sub-magnetosonic. Observational analysis of turbulent flows in the magnetotail usually assume that the Taylor frozen-in-flow hypothesis is valid and compare power spectral density vs. frequency with spectral indices derived for fluid turbulence by Kolmogorov in 1941. Global simulations carried out for actual magnetospheric substorms in the tail enable the results of the simulations to be compared directly with observed power spectra. The agreement between the two techniques provides confidence that the plasma sheet plasma is actually turbulent. The MHD results also allow us to calculate the power vs. wave number; results that also support the idea that the tail is turbulent. | en_US |
| dc.description.sponsorship | This work was supported by NASA NNX17AB83G and NSF-2040319. We also acknowledge NASA THEMIS contract NAS5-02099 and NASA HPDE contract 80GSFC17C0018 at UCL. The MHD computations were performed by using the Comet supercomputer at San Diego, part of the Extreme Science and Engineering Discovery Environment (XSEDE). This program is supported by grant number ACI-1548562 from the National Science Foundation. The data produced by the simulations are stored on local machines and are available upon request to the lead author. | en_US |
| dc.description.uri | https://www.frontiersin.org/articles/10.3389/fspas.2021.620519/full | en_US |
| dc.format.extent | 16 pages | en_US |
| dc.genre | journal articles | en_US |
| dc.identifier | doi:10.13016/m2vwuj-biwq | |
| dc.identifier.citation | El-Alaoui M, Walker RJ, Weygand JM, Lapenta G and Goldstein ML (2021) Magnetohydrodynamic Turbulence in the Earth’s Magnetotail From Observations and Global MHD Simulations. Front. Astron. Space Sci. 8:620519. doi: 10.3389/fspas.2021.620519 | en_US |
| dc.identifier.uri | https://doi.org/10.3389/fspas.2021.620519 | |
| dc.identifier.uri | http://hdl.handle.net/11603/25560 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | Frontiers | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Goddard Planetary Heliophysics Institute (GPHI) | |
| dc.relation.ispartof | UMBC Faculty Collection | |
| dc.rights | This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author. | en_US |
| dc.rights | Attribution 4.0 International (CC BY 4.0) | * |
| dc.rights.uri | https://creativecommons.org/licenses/by/4.0/ | * |
| dc.title | Magnetohydrodynamic Turbulence in the Earth’s Magnetotail From Observations and Global MHD Simulations | en_US |
| dc.type | Text | en_US |
| dcterms.creator | https://orcid.org/0000-0002-5317-988X | en_US |