Plasma wave signatures in the magnetotail reconnection region: MHD simulation and ray tracing

1993 ◽  
Vol 98 (A6) ◽  
pp. 9189 ◽  
Author(s):  
Yoshiharu Omura ◽  
James L. Green
Keyword(s):  
Ray Tracing ◽  
Plasma Wave ◽  
Mhd Simulation ◽  
Reconnection Region ◽  
Magnetotail Reconnection

scholarly journals Particle Acceleration in Earth’s Global Magnetosphere: a Multiple Step Process

2020 ◽  
Author(s):  
Robert L. Richard ◽  
David Schriver ◽  
Jean Berchem ◽  
Mostafa El-Alaoui ◽  
Giovanni Lapenta ◽  
...  
Keyword(s):  
Large Scale ◽  
High Energy ◽  
Distribution Functions ◽  
Time Interval ◽  
Additional Energy ◽  
Mhd Simulation ◽  
Pic Simulation ◽  
Reconnection Region ◽  
Magnetotail Reconnection ◽  
Suprathermal Particles

<p>Particle velocity distribution functions measured by spacecraft show that suprathermal ion and electron populations are a common feature of Earth’s magnetosphere.  An outstanding question has been to determine the acceleration processes that lead to the formation of these suprathermal particle populations. Very often, it has been challenging to explain the high levels of energy reached by these particles by simply invoking local processes such as magnetic reconnection. In this presentation, we investigate the hypothesis that suprathermal particle populations increase if the acceleration occurs over multiple steps through different acceleration mechanisms at different spatial locations in Earth’s magnetosphere.  For example, particles transported to the magnetotail which have been accelerated first in the dayside reconnection region could be further accelerated in the tail reconnection regions and then gain additional energy through Fermi and/or betatron acceleration as they convected back to the dayside magnetopause. Since local kinetic processes dominate the acceleration of ions and electrons in the magnetosphere, it has been difficult to validate that hypothesis. Multiple reconnection sites and different possible acceleration regions are too distant to be included in a single kinetic simulation and global hybrid simulations cannot describe electron acceleration.  To address this research problem we leverage our simulation capabilities by combining three different simulation techniques: global magnetohydrodynamic (MHD) simulations, large-scale kinetic (LSK) particle tracing simulations, and large-scale particle in cell (PIC) simulations.  First, we carry out an MHD simulation driven by upstream solar wind and interplanetary magnetic field conditions for a specific time interval featuring active magnetospheric reconnection.  Then we use an implicit PIC simulation of dayside reconnection with initial and boundary conditions from the MHD simulation.  Next, we follow suprathermal particles from the PIC simulation globally through the MHD fields using LSK to assess their transport into the magnetotail. A final step is to perform a PIC simulation embedded in the MHD simulation of magnetotail process including the suprathermal particles arriving from the dayside as determined from the LSK simulation.  Preliminary results indicate that particles energized by dayside reconnection are more likely to reach the magnetotail reconnection region. In addition, the development of enhanced high-energy tails in the particle distributions is promoted by previous energization steps during particle transport to the magnetotail reconnection region.</p>

scholarly journals The magnetotail reconnection region in a global MHD simulation

2005 ◽  
Vol 23 (12) ◽  
pp. 3753-3764 ◽  
Author(s):  
T. V. Laitinen ◽  
T. I. Pulkkinen ◽  
M. Palmroth ◽  
P. Janhunen ◽  
H. E. J. Koskinen
Keyword(s):  
Current Sheet ◽  
Magnetic Energy ◽  
Sheet Thickness ◽  
Poynting Flux ◽  
Reconnection Region ◽  
Magnetohydrodynamic Simulation ◽  
Global Mhd Simulation ◽  
The Difference ◽  
Magnetotail Reconnection

Abstract. This work investigates the nature and the role of magnetic reconnection in a global magnetohydrodynamic simulation of the magnetosphere. We use the Gumics-4 simulation to study reconnection that occurs in the near-Earth region of the current sheet in the magnetotail. We locate the current sheet surface and the magnetic x-line that appears when reconnection starts. We illustrate the difference between quiet and active states of the reconnection region: variations in such quantities as the current sheet thickness, plasma flow velocities, and Poynting vector divergence are strong. A characteristic feature is strong asymmetry caused by non-perpendicular inflows. We determine the reconnection efficiency by the net rate of Poynting flux into the reconnection region. The reconnection efficiency in the simulation is directly proportional to the energy flux into the magnetosphere through the magnetopause: about half of all energy flowing through the magnetosphere is converted from an electromagnetic into a mechanical form in the reconnection region. Thus, the tail reconnection that is central to the magnetospheric circulation is directly driven; the tail does not exhibit a cycle of storage and rapid release of magnetic energy. We find similar behaviour of the tail in both synthetic and real event runs.

Occurrence rate of whistler waves in the magnetotail reconnection region

2017 ◽  
Vol 122 (7) ◽  
pp. 7188-7196 ◽  
Author(s):  
S. Y. Huang ◽  
Z. G. Yuan ◽  
F. Sahraoui ◽  
H. S. Fu ◽  
Y. Pang ◽  
...  
Keyword(s):  
Occurrence Rate ◽  
Whistler Waves ◽  
Reconnection Region ◽  
Magnetotail Reconnection

scholarly journals Energetic particles in magnetotail reconnection

2014 ◽  
Vol 81 (2) ◽  
Author(s):  
Ivy Bo Peng ◽  
Juris Vencels ◽  
Giovanni Lapenta ◽  
Andrey Divin ◽  
Andris Vaivads ◽  
...  
Keyword(s):  
Magnetic Reconnection ◽  
Energetic Particles ◽  
Lower Hybrid ◽  
Electron Trajectory ◽  
Strong Electron ◽  
Energetic Electrons ◽  
Particle In Cell ◽  
Reconnection Region ◽  
Magnetotail Reconnection ◽  
Drift Instability

We carried out a 3D fully kinetic simulation of Earth's magnetotail magnetic reconnection to study the dynamics of energetic particles. We developed and implemented a new relativistic particle mover in iPIC3D, an implicit Particle-in-Cell code, to correctly model the dynamics of energetic particles. Before the onset of magnetic reconnection, energetic electrons are found localized close to current sheet and accelerated by lower hybrid drift instability. During magnetic reconnection, energetic particles are found in the reconnection region along thex-line and in the separatrices region. The energetic electrons are first present in localized stripes of the separatrices and finally cover all the separatrix surfaces. Along the separatrices, regions with strong electron deceleration are found. In the reconnection region, two categories of electron trajectory are identified. First, part of the electrons are trapped in the reconnection region, bouncing a few times between the outflow jets. Second, part of the electrons pass the reconnection region without being trapped. Different from electrons, energetic ions are localized on the reconnection fronts of the outflow jets.

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