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Title: Drift turbulence, particle transport, and anomalous dissipation at the reconnecting magnetopause

Here, using fully kinetic 3D simulations, the reconnection dynamics of asymmetric current sheets are examined at the Earth's magnetopause. The plasma parameters are selected to model MMS magnetopause diffusion region crossings with guide fields of 0.1, 0.4, and 1 of the reconnecting magnetosheath field. In each case, strong drift-wave fluctuations are observed in the lower-hybrid frequency range at the steep density gradient across the magnetospheric separatrix. These fluctuations give rise to cross-field electron particle transport. In addition, this turbulent mixing leads to significantly enhanced electron parallel heating in comparison to 2D simulations. We study three different methods of quantifying the anomalous dissipation produced by the drift fluctuations, based on spatial averaging, temporal averaging, and temporal averaging followed by integrating along magnetic field lines. A comparison of different methods reveals complications in identifying and measuring the anomalous dissipation. Nevertheless, the anomalous dissipation from short wavelength drift fluctuations appears weak for each case, and the reconnection rates observed in 3D are nearly the same as in 2D models. Finally, the 3D simulations feature a number of interesting new features that are consistent with recent MMS observations, including cold beams of magnetosheath electrons that penetrate into the hotter magnetospheric inflow, the related observationmore » of decreasing temperature in regions of increasing total density, and an effective turbulent diffusion coefficient that agrees with predictions from quasi-linear theory.« less
Authors:
ORCiD logo [1] ;  [1] ;  [1] ;  [2] ; ORCiD logo [3] ; ORCiD logo [2] ;  [1] ;  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Univ. of Maryland, College Park, MD (United States); NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
  3. Dartmouth College, Hanover, NH (United States)
Publication Date:
Report Number(s):
LA-UR-18-21459
Journal ID: ISSN 1070-664X
Grant/Contract Number:
AC52-06NA25396; NNX14AL38G; NNH17AE36I; NNH13AW51I; NNX16AG75G
Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 25; Journal Issue: 6; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dartmouth College, Hanover, NH (United States); NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
Sponsoring Org:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24); LANL Laboratory Directed Research and Development (LDRD) Program; National Aeronautic and Space Administration (NASA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 79 ASTRONOMY AND ASTROPHYSICS; magnetic reconnection; plasma waves; magnetospheric dynamics; spacecrafts; magnetopause; plasma instabilities
OSTI Identifier:
1477696
Alternate Identifier(s):
OSTI ID: 1439392

Le, A., Daughton, W., Ohia, O., Chen, L. -J., Liu, Y. -H., Wang, S., Nystrom, W. D., and Bird, R.. Drift turbulence, particle transport, and anomalous dissipation at the reconnecting magnetopause. United States: N. p., Web. doi:10.1063/1.5027086.
Le, A., Daughton, W., Ohia, O., Chen, L. -J., Liu, Y. -H., Wang, S., Nystrom, W. D., & Bird, R.. Drift turbulence, particle transport, and anomalous dissipation at the reconnecting magnetopause. United States. doi:10.1063/1.5027086.
Le, A., Daughton, W., Ohia, O., Chen, L. -J., Liu, Y. -H., Wang, S., Nystrom, W. D., and Bird, R.. 2018. "Drift turbulence, particle transport, and anomalous dissipation at the reconnecting magnetopause". United States. doi:10.1063/1.5027086.
@article{osti_1477696,
title = {Drift turbulence, particle transport, and anomalous dissipation at the reconnecting magnetopause},
author = {Le, A. and Daughton, W. and Ohia, O. and Chen, L. -J. and Liu, Y. -H. and Wang, S. and Nystrom, W. D. and Bird, R.},
abstractNote = {Here, using fully kinetic 3D simulations, the reconnection dynamics of asymmetric current sheets are examined at the Earth's magnetopause. The plasma parameters are selected to model MMS magnetopause diffusion region crossings with guide fields of 0.1, 0.4, and 1 of the reconnecting magnetosheath field. In each case, strong drift-wave fluctuations are observed in the lower-hybrid frequency range at the steep density gradient across the magnetospheric separatrix. These fluctuations give rise to cross-field electron particle transport. In addition, this turbulent mixing leads to significantly enhanced electron parallel heating in comparison to 2D simulations. We study three different methods of quantifying the anomalous dissipation produced by the drift fluctuations, based on spatial averaging, temporal averaging, and temporal averaging followed by integrating along magnetic field lines. A comparison of different methods reveals complications in identifying and measuring the anomalous dissipation. Nevertheless, the anomalous dissipation from short wavelength drift fluctuations appears weak for each case, and the reconnection rates observed in 3D are nearly the same as in 2D models. Finally, the 3D simulations feature a number of interesting new features that are consistent with recent MMS observations, including cold beams of magnetosheath electrons that penetrate into the hotter magnetospheric inflow, the related observation of decreasing temperature in regions of increasing total density, and an effective turbulent diffusion coefficient that agrees with predictions from quasi-linear theory.},
doi = {10.1063/1.5027086},
journal = {Physics of Plasmas},
number = 6,
volume = 25,
place = {United States},
year = {2018},
month = {5}
}