The influence of kinetic effect on the MHD scalings of a thin current sheet

2017 ◽  
Vol 122 (1) ◽  
pp. 493-500 ◽  
Author(s):  
Yu. L. Sasunov ◽  
M. L. Khodachenko ◽  
I. I. Alexeev ◽  
E. S. Belenkaya ◽  
O. V. Mingalev ◽  
...  
Keyword(s):  
Current Sheet ◽  
Kinetic Effect ◽  
Thin Current Sheet

Global and local processes of thin current sheet formation during substorm growth phase

2021 ◽  
pp. 105671
Author(s):  
A. Runov ◽  
V. Angelopoulos ◽  
A.V. Artemyev ◽  
J.M. Weygand ◽  
S. Lu ◽  
...  
Keyword(s):  
Current Sheet ◽  
Growth Phase ◽  
Thin Current Sheet ◽  
Global And Local

Cluster Observation of Electrostatic Solitary Waves around Magnetic Null Point in Thin Current Sheet

2010 ◽  
Vol 27 (1) ◽  
pp. 019401 ◽  
Author(s):  
Li Shi-You ◽  
Deng Xiao-Hua ◽  
Zhou Meng ◽  
Yuan Zhi-Gang ◽  
Wang Jing-Fang ◽  
...  
Keyword(s):  
Current Sheet ◽  
Solitary Waves ◽  
Null Point ◽  
Thin Current Sheet ◽  
Magnetic Null ◽  
Magnetic Null Point

Statistics on Jupiter's Current Sheet with Juno Data: Geometry, Magnetic Fields and Energetic Particles

2021 ◽  
Author(s):  
Zhi-Yang Liu ◽  
Qiu-Gang Zong ◽  
Michel Blanc
Keyword(s):  
Magnetic Fields ◽  
Current Sheet ◽  
Power Law ◽  
Heavy Ions ◽  
Particle Interaction ◽  
The Other ◽  
Gaussian Functions ◽  
Fixed Energy ◽  
Thin Current Sheet ◽  
A Current

<p>Jupiter's magnetosphere contains a current sheet of huge size near its equator. The current sheet not only mediates the global mass and energy cycles of Jupiter's magnetosphere, but also provides an occurring place for many localized dynamic processes, such as reconnection and wave-particle interaction. To correctly evaluate its role in these processes, a statistical description of the current sheet is required. To this end, here we conduct statistics on Jupiter's current sheet, with four-year Juno data recorded in the 20-100 Jupiter radii, post-midnight magnetosphere. The results suggest a thin current sheet whose thickness is comparable with the gyro-radius of dominant ions. Magnetic fields in the current sheet decrease in power-law with increasing radial distances. At fixed energy, the flux of electrons and protons increases with decreasing radial distances. On the other hand, at fixed radial distances, the flux decreases in power-law with increasing energy. The flux also varies with the distances to the current sheet center. The corresponding relationship can be well described by Gaussian functions peaking at the current sheet center. In addition, the statistics show the flux of oxygen- and sulfur-group ions is comparable with the flux of protons at the same energy and radial distances, indicating the non-negligible effects of heavy ions on current sheet dynamics. From these results, a statistical model of Jupiter's current sheet is constructed, which provides us with a start point of understanding the dynamics of the whole Jupiter's magnetosphere.</p>

scholarly journals Instabilities in a thin current sheet and their consequences

2004 ◽  
Vol 11 (2) ◽  
pp. 153-163 ◽  
Author(s):  
N. Singh
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Drift Velocity ◽  
Early Stage ◽  
Field Configuration ◽  
Central Plane ◽  
Current Disruption ◽  
Electrons And Ions ◽  
Thin Current Sheet ◽  
Electrostatic Fluctuations

Abstract. Using a fully 3-D particle in-cell simulation, we studied the electrodynamics of a thin current sheet (CS). Starting with a uniform plasma and anti-parallel magnetic field, Harris equilibrium is achieved during the early stage of the simulation. In the processes of reaching the equilibrium, both electrons and ions in the newly formed CS are energized and develop pitch-angle anisotropies. We find two distinct stages of primarily electrostatic instabilities; in the first stage the relative drift between electrons and ions drives the instability in the central regions of the CS. The electrostatic fluctuations scatter electrons causing current disruption in the central region. The associated reduction in the average drift velocity of the current-carrying electrons generates sheared flow. The second stage of the instability begins when the drift velocity develops a minimum in the central plane. Then the shear and the growing electrostatic fluctuations under the condition of the maintained anti-parallel driving magnetic field configuration feed each other making the instability explosive. The growing fluctuations create plasma clumps as the electrons and ions are progressively trapped in the large-amplitude waves. The density clumping also generates clumps in the current. The non-uniform current distribution causes magnetic reconnection, accompanied by heating of electrons and ion at a fast rate and nearly complete bifurcation of the current sheet. Anomalous resistivity during different stages of the evolution of the CS is calculated and compared against theory.

scholarly journals Nonlinear equilibrium structure of thin currents sheets: influence of electron pressure anisotropy

2004 ◽  
Vol 11 (5/6) ◽  
pp. 579-587 ◽  
Author(s):  
L. M. Zelenyi ◽  
H. V. Malova ◽  
V. Yu. Popov ◽  
D. Delcourt ◽  
A. S. Sharma
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Magnetic Energy ◽  
Plasma Pressure ◽  
Quasi Equilibrium ◽  
Electrostatic Effects ◽  
Current Sheets ◽  
Thin Current Sheet ◽  
Field Lines ◽  
The Magnetic Field

Abstract. Thin current sheets represent important and puzzling sites of magnetic energy storage and subsequent fast release. Such structures are observed in planetary magnetospheres, solar atmosphere and are expected to be widespread in nature. The thin current sheet structure resembles a collapsing MHD solution with a plane singularity. Being potential sites of effective energy accumulation, these structures have received a good deal of attention during the last decade, especially after the launch of the multiprobe CLUSTER mission which is capable of resolving their 3D features. Many theoretical models of thin current sheet dynamics, including the well-known current sheet bifurcation, have been developed recently. A self-consistent 1D analytical model of thin current sheets in which the tension of the magnetic field lines is balanced by the ion inertia rather than by the plasma pressure gradients was developed earlier. The influence of the anisotropic electron population and of the corresponding electrostatic field that acts to restore quasi-neutrality of the plasma is taken into account. It is assumed that the electron motion is fluid-like in the direction perpendicular to the magnetic field and fast enough to support quasi-equilibrium Boltzmann distribution along the field lines. Electrostatic effects lead to an interesting feature of the current density profile inside the current sheet, i.e. a narrow sharp peak of electron current in the very center of the sheet due to fast curvature drift of the particles in this region. The corresponding magnetic field profile becomes much steeper near the neutral plane although the total cross-tail current is in all cases dominated by the ion contribution. The dependence of electrostatic effects on the ion to electron temperature ratio, the curvature of the magnetic field lines, and the average electron magnetic moment is also analyzed. The implications of these effects on the fine structure of thin current sheets and their potential impact on substorm dynamics are presented.

scholarly journals Observations of an active thin current sheet

2008 ◽  
Vol 113 (A7) ◽  
pp. n/a-n/a ◽  
Author(s):  
A. Runov ◽  
W. Baumjohann ◽  
R. Nakamura ◽  
V. A. Sergeev ◽  
O. Amm ◽  
...  
Keyword(s):  
Current Sheet ◽  
Thin Current Sheet

scholarly journals Tailward and earthward flow onsets observed by Cluster in a thin current sheet

2009 ◽  
Vol 114 (A9) ◽  
pp. n/a-n/a ◽  
Author(s):  
A. A. Petrukovich ◽  
W. Baumjohann ◽  
R. Nakamura ◽  
H. Rème
Keyword(s):  
Current Sheet ◽  
Thin Current Sheet ◽  
Earthward Flow

First demonstration of an asymmetric kinetic equilibrium for a thin current sheet

2013 ◽  
Vol 20 (11) ◽  
pp. 110702 ◽  
Author(s):  
Nicolas Aunai ◽  
Gerard Belmont ◽  
Roch Smets
Keyword(s):  
Current Sheet ◽  
Thin Current Sheet ◽  
Kinetic Equilibrium

Lower-hybrid drift instability in a thin current sheet with κ velocity distribution

2009 ◽  
Vol 16 (4) ◽  
pp. 042107 ◽  
Author(s):  
Feng Huang ◽  
Yinhua Chen ◽  
Guifen Shi ◽  
Zuquan Hu ◽  
Haiou Peng ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
Current Sheet ◽  
Lower Hybrid ◽  
Thin Current Sheet ◽  
Drift Instability
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