scholarly journals Fluid simulations of three-dimensional reconnection that capture the lower-hybrid drift instability

2021 ◽  
Vol 87 (1) ◽  
Author(s):  
F. Allmann-Rahn ◽  
S. Lautenbach ◽  
R. Grauer ◽  
R. D. Sydora

Fluid models that approximate kinetic effects have received attention recently in the modelling of large-scale plasmas such as planetary magnetospheres. In three-dimensional reconnection, both reconnection itself and current sheet instabilities need to be represented appropriately. We show that a heat flux closure based on pressure gradients enables a 10-moment fluid model to capture key properties of the lower-hybrid drift instability (LHDI) within a reconnection simulation. Characteristics of the instability are examined with kinetic and fluid continuum models, and its role in the three-dimensional reconnection simulation is analysed. The saturation level of the electromagnetic LHDI is higher than expected, which leads to strong kinking of the current sheet. Therefore, the magnitude of the initial perturbation has significant impact on the resulting turbulence.

2018 ◽  
Vol 619 ◽  
pp. A82
Author(s):  
Man Zhang ◽  
Yu Fen Zhou ◽  
Xue Shang Feng ◽  
Bo Li ◽  
Ming Xiong

In this paper, we have used a three-dimensional numerical magnetohydrodynamics model to study the reconnection process between magnetic cloud and heliospheric current sheet. Within a steady-state heliospheric model that gives a reasonable large-scale structure of the solar wind near solar minimum, we injected a spherical plasmoid to mimic a magnetic cloud. When the magnetic cloud moves to the heliospheric current sheet, the dynamic process causes the current sheet to become gradually thinner and the magnetic reconnection begin. The numerical simulation can reproduce the basic characteristics of the magnetic reconnection, such as the correlated/anticorrelated signatures in V and B passing a reconnection exhaust. Depending on the initial magnetic helicity of the cloud, magnetic reconnection occurs at points along the boundary of the two systems where antiparallel field lines are forced together. We find the magnetic filed and velocity in the MC have a effect on the reconnection rate, and the magnitude of velocity can also effect the beginning time of reconnection. These results are helpful in understanding and identifying the dynamic process occurring between the magnetic cloud and the heliospheric current sheet.


2010 ◽  
Vol 17 (10) ◽  
pp. 102102 ◽  
Author(s):  
Dandan Zou ◽  
Weihong Yang ◽  
Yinhua Chen ◽  
P. H. Yoon

1999 ◽  
Vol 17 (5) ◽  
pp. 604-612 ◽  
Author(s):  
J. Büchner ◽  
J.-P. Kuska

Abstract. Observations have shown that, prior to substorm explosions, thin current sheets are formed in the plasma sheet of the Earth's magnetotail. This provokes the question, to what extent current-sheet thinning and substorm onsets are physically, maybe even causally, related. To answer this question, one has to understand the plasma stability of thin current sheets. Kinetic effects must be taken into account since particle scales are reached in the course of tail current-sheet thinning. We present the results of theoretical investigations of the stability of thin current sheets and about the most unstable mode of their decay. Our conclusions are based upon a non-local linear dispersion analysis of a cross-magnetic field instability of Harris-type current sheets. We found that a sausage-mode bulk current instability starts after a sheet has thinned down to the ion inertial length. We also present the results of three-dimensional electromagnetic PIC-code simulations carried out for mass ratios up to Mi / me=64. They verify the linearly predicted properties of the sausage mode decay of thin current sheets in the parameter range of interest.Key words. Magnetospheric physics (plasma waves and instabilities; storms and substorms) · Space plasma physics (magnetic reconnection)


2009 ◽  
Vol 16 (4) ◽  
pp. 042107 ◽  
Author(s):  
Feng Huang ◽  
Yinhua Chen ◽  
Guifen Shi ◽  
Zuquan Hu ◽  
Haiou Peng ◽  
...  

2014 ◽  
Vol 81 (1) ◽  
Author(s):  
P. L. Sulem ◽  
T. Passot

With the aim to develop a tool for simulating turbulence in collisionless magnetized plasmas, fluid models retaining low-frequency kinetic effects such as Landau damping and finite Larmor radius (FLR) corrections are discussed. It turns out that, in the absence of ion-cyclotron resonance, the dispersion and damping of kinetic Alfvén waves at scales as small as a fraction of the ion Larmor radius are accurately reproduced when using fluid estimates of the non-gyrotropic moments, at leading-order within a large-scale asymptotics. Differently, evaluations based on the low-frequency linear kinetic theory are necessary in regimes of large temperature anisotropies, and in particular in the presence of the mirror instability. Combining both descriptions leads to a new Landau fluid model retaining large-scale FLR nonlinearities, while reproducing the linear dynamics of low-frequency modes at the sub-ionic scales.


2013 ◽  
Vol 87 (6) ◽  
pp. 065501 ◽  
Author(s):  
Feng Huang ◽  
Guohong Liu ◽  
Yinhua Chen ◽  
M Y Yu ◽  
Fei Yan ◽  
...  

2008 ◽  
Vol 10 (4) ◽  
pp. 416-421
Author(s):  
Hu Youjun ◽  
Yang Weihong ◽  
Chen Yinhua ◽  
Huang Feng ◽  
Wang Feihu ◽  
...  

2021 ◽  
Author(s):  
Florian Allmann-Rahn ◽  
Simon Lautenbach ◽  
Richard Sydora ◽  
Rainer Grauer

<p>The electromagnetic branch of the lower-hybrid drift instability (LHDI) can lead to kinking of current sheets and fluctuations in the magnetic field and is present for example in Earth’s magnetosphere. Previous particle-in-cell studies suggested that the electromagnetic LHDI’s saturation is at a moderate level and that strong current sheet kinking is only caused by slower kink-type modes. Here, we present kinetic continuum simulations that show strong kinking and high saturation levels of the B-field fluctuations. Has the impact of the electromagnetic LHDI been underestimated? The capability of the LHDI to produce x-lines and turbulence in 3D reconnection is discussed at the example of ten-moment multi-fluid simulations.</p>


2008 ◽  
Vol 15 (11) ◽  
pp. 112103 ◽  
Author(s):  
P. H. Yoon ◽  
Y. Lin ◽  
X. Y. Wang ◽  
A. T. Y. Lui

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