Magnetic reconnection in Earth's magnetotail: Energy conversion and its earthward–tailward asymmetry

2018 ◽  
Vol 25 (1) ◽  
pp. 012905 ◽  
Author(s):  
San Lu ◽  
P. L. Pritchett ◽  
V. Angelopoulos ◽  
A. V. Artemyev
Keyword(s):  
Energy Conversion ◽  
Magnetic Reconnection

Micro-scale tearing mode turbulence in the diffusion region during macro-scale evolution of turbulent reconnection

2021 ◽  
Author(s):  
Takuma Nakamura ◽  
Hiroshi Hasegawa ◽  
Tai Phan ◽  
Kevin Genestreti ◽  
Richard Denton ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energy Conversion ◽  
Magnetic Reconnection ◽  
Diffusion Region ◽  
Electron Diffusion ◽  
Efficient Energy ◽  
Micro Scale ◽  
Island Evolution ◽  
Macro Scale ◽  
Scale Evolution

<p>Magnetic reconnection is a key fundamental process in collisionless plasmas that explosively converts magnetic energy to plasma kinetic and thermal energies through a change of magnetic field topology in an electron-scale central region called the electron diffusion region. Past simulations and observations demonstrated that this process causes efficient energy conversion through the formation of multiple macro-scale or micro-scale magnetic islands/flux ropes. However, how these different spatiotemporal scale phenomena are coupled is still poorly understood. In this study, to investigate the turbulent evolution of magnetic reconnection, we perform a new large-scale fully kinetic simulation of a thin current sheet considering a power-law spectrum of initial fluctuations in the magnetic field as frequently observed in the Earth’s magnetotail. The simulation demonstrates that during a macro-scale evolution of turbulent reconnection, the merging of macro-scale islands results in reduction of the rate of reconnection as well as the aspect ratio of the electron diffusion region. This allows the repeated, quick formation of new electron-scale islands within the electron diffusion region, leading to an efficient energy cascade between macro- and micro-scales. The simulation also demonstrates that a strong electron acceleration/heating occurs during the micro-scale island evolution within the EDR. These new findings indicate the importance of non-steady features of the EDR to comprehensively understand the energy conversion and cascade processes in collisionless reconnection.</p>

scholarly journals Collisionless magnetic reconnection in the presence of an external driving flow

1999 ◽  
Vol 61 (3) ◽  
pp. 415-423 ◽  
Author(s):  
RITOKU HORIUCHI ◽  
TETSUYA SATO
Keyword(s):  
Magnetic Field ◽  
Energy Conversion ◽  
Magnetic Reconnection ◽  
Late Phase ◽  
Collisionless Plasma ◽  
Phase Changes ◽  
Particle Simulation ◽  
Inertia Effect ◽  
Kinetic Effect ◽  
External Driving

The dynamical development of collisionless reconnection and the consequent energy-conversion process in the presence of an external driving flow are investigated by means of a full particle simulation. Magnetic reconnection develops in two steps in accordance with the formation of ion and electron current layers. In the early phase magnetic reconnection is controlled by an ion kinetic effect, while an electron kinetic effect becomes dominant in the late phase. There exist two mechanisms associated with the particle kinetic effects, that break the frozen-in condition of magnetic field and lead to magnetic reconnection in a collisionless plasma, namely a particle inertia effect and a particle thermal orbit effect. It is found that the dominant triggering mechanism in the late phase changes from an electron thermal orbit effect to an electron inertia effect as the longitudinal magnetic field increases. Electron acceleration and heating take place in the reconnection area under the influence of the reconnection electric field, while the energy conversion takes place from electrons to ions through the action of an electrostatic field excited downstream. As a result, the average ion temperature becomes about 1.5 times the average electron temperature.

scholarly journals The Effect of a Guide Field on Local Energy Conversion During Asymmetric Magnetic Reconnection: MMS Observations

2017 ◽  
Vol 122 (11) ◽  
pp. 11,342-11,353 ◽  
Author(s):  
K. J. Genestreti ◽  
J. L. Burch ◽  
P. A. Cassak ◽  
R. B. Torbert ◽  
R. E. Ergun ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Magnetic Reconnection ◽  
Local Energy ◽  
Guide Field

scholarly journals Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasmaa)

2015 ◽  
Vol 22 (5) ◽  
pp. 056501 ◽  
Author(s):  
Masaaki Yamada ◽  
Jongsoo Yoo ◽  
Jonathan Jara-Almonte ◽  
William Daughton ◽  
Hantao Ji ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Magnetic Reconnection ◽  
Reconnection Layer

scholarly journals Search for an onset mechanism that operates for both CMEs and substorms

2009 ◽  
Vol 27 (8) ◽  
pp. 3141-3146 ◽  
Author(s):  
G. L. Siscoe ◽  
M. M. Kuznetsova ◽  
J. Raeder
Keyword(s):  
Energy Conversion ◽  
Magnetic Reconnection ◽  
Sudden Onset ◽  
Explosive Energy ◽  
Sequence Of Events ◽  
Mhd Simulations ◽  
Significant Difference ◽  
Single Process ◽  
Outward Motion ◽  
Rapid Expulsion

Abstract. Substorms and coronal mass ejections have been cited as the most accessible examples of the explosive energy conversion phenomenon that seems to characterize one of the behavior modes of cosmic plasmas. This paper addresses the question of whether these two examples – substorms and CMEs – support or otherwise the idea that explosive energy conversion is the result of a single process operating in different places and under different conditions. As a candidate mechanism that might be common to both substorms and CMEs we use the Forbes catastrophe model for CMEs because before testing it appears to have the potential, suitably modified, to operate also for substorms. The essence of the FCM is a sudden onset of an imbalance of the forces acting on an incipient CME. The imbalance of forces causes the CME to start to rise. Beneath the rising CME conditions develop that favor the onset of magnetic reconnection which then releases the CME and assists its expulsion. Thus the signature of the FCM is a temporally ordered sequence in which there is first the appearance of force imbalance which leads to upward (or outward) motion of the CME which leads to magnetic reconnection under it which expedites rapid expulsion. We look for the FCM signature in the output of two global magnetospheric MHD simulations that produce substorm-like events. We find the ordered sequence of events as stated but with a significant difference: there is no plasmoid prior to the onset of rapid reconnection, that is, there is no counterpart to the incipient CME on which an imbalance of forces acts to initiate the action in the FCM. If this result – that rapid tailward motion precedes the rapid reconnection of substorm expansion – is ultimately verified by other studies, it suggests that a description of the cause of substorm expansion should identify the cause of the preceding rapid tailward motion, since this leads necessarily to rapid reconnection, whatever the reconnection mechanism turns out to be. Clearly then, it is important to identify the cause of the preceding tailward motion.

scholarly journals The Effect of a Guide Field on Local Energy Conversion During Asymmetric Magnetic Reconnection: Particle-in-Cell Simulations

2017 ◽  
Vol 122 (11) ◽  
pp. 11,523-11,542 ◽  
Author(s):  
P. A Cassak ◽  
K. J. Genestreti ◽  
J. L Burch ◽  
T.-D. Phan ◽  
M. A. Shay ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Magnetic Reconnection ◽  
Local Energy ◽  
Particle In Cell ◽  
Guide Field

scholarly journals Localized and Intense Energy Conversion in the Diffusion Region of Asymmetric Magnetic Reconnection

2018 ◽  
Vol 45 (11) ◽  
pp. 5260-5267 ◽  
Author(s):  
M. Swisdak ◽  
J. F. Drake ◽  
L. Price ◽  
J. L. Burch ◽  
P. A. Cassak ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Magnetic Reconnection ◽  
Diffusion Region
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