Mirror mode structures ahead of dipolarization front near the neutral sheet observed by Cluster

2016 ◽  
Vol 43 (17) ◽  
pp. 8853-8858 ◽  
Author(s):  
G. Q. Wang ◽  
T. L. Zhang ◽  
M. Volwerk ◽  
D. Schmid ◽  
W. Baumjohann ◽  
...  
Keyword(s):  
Neutral Sheet ◽  
Dipolarization Front ◽  
Mirror Mode

Observations of Mirror Mode Structures in the Dawn‐side Magnetosphere

2020 ◽  
Author(s):  
M. O. Chandler ◽  
S. J. Schwartz ◽  
L. A. Avanov ◽  
V. N. Coffey ◽  
B. L. Giles ◽  
...  
Keyword(s):  
Mirror Mode

scholarly journals Propagation of an MHD Shock in the Vicinity of a Magnetic Neutral Sheet

1980 ◽  
Vol 91 ◽  
pp. 323-326
Author(s):  
D. J. Mullan ◽  
R. S. Steinolfson
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Solar Corona ◽  
Large Scale ◽  
Field Structure ◽  
Neutral Sheet ◽  
Solar Cosmic Rays ◽  
Magnetic Field Structure ◽  
Large Scale Magnetic Field ◽  
Highly Correlated

The acceleration of solar cosmic rays in association with certain solar flares is known to be highly correlated with the propagation of an MHD shock through the solar corona (Svestka, 1976). The spatial structure of the sources of solar cosmic rays will be determined by those regions of the corona which are accessible to the flare-induced shock. The regions to which the flare shock is permitted to propagate are determined by the large scale magnetic field structure in the corona. McIntosh (1972, 1979) has demonstrated that quiescent filaments form a single continuous feature (a “baseball stitch”) around the surface of the sun. It is known that helmet streamers overlie quiescent filaments (Pneuman, 1975), and these helmet streamers contain large magnetic neutral sheets which are oriented essentially radially. Hence the magnetic field structure in the low solar corona is characterized by a large-scale radial neutral sheet which weaves around the entire sun following the “baseball stitch”. There is therefore a high probability that as a shock propagates away from a flare, it will eventually encounter this large neutral sheet.

First identification of mirror mode waves in Venus' magnetosheath?

2008 ◽  
Vol 35 (12) ◽  
pp. n/a-n/a ◽  
Author(s):  
M. Volwerk ◽  
T. L. Zhang ◽  
M. Delva ◽  
Z. Vörös ◽  
W. Baumjohann ◽  
...  
Keyword(s):  
Mirror Mode

scholarly journals Periodic black auroral patches at the dawnside dipolarization front during a substorm

2011 ◽  
Vol 116 (A5) ◽  
Author(s):  
K. Sakaguchi ◽  
K. Shiokawa ◽  
E. Donovan ◽  
A. Nakajima ◽  
Y. Hiraki ◽  
...  
Keyword(s):  
Dipolarization Front

Wave-particle interactions in a magnetic neutral sheet

1981 ◽  
Vol 29 (4) ◽  
pp. 399-403 ◽  
Author(s):  
C. Robertson ◽  
S.W.H. Cowley ◽  
J.W. Dungey
Keyword(s):  
Particle Interactions ◽  
Neutral Sheet ◽  
Wave Particle Interactions

scholarly journals Magnetic Decreases (MDs) and mirror modes: two different plasma β changing mechanisms

2010 ◽  
Vol 17 (5) ◽  
pp. 467-479 ◽  
Author(s):  
B. T. Tsurutani ◽  
G. S. Lakhina ◽  
O. P. Verkhoglyadova ◽  
E. Echer ◽  
F. L. Guarnieri
Keyword(s):  
Free Energy ◽  
Energetic Particle ◽  
Ponderomotive Force ◽  
Interplanetary Space ◽  
The Other ◽  
Characteristic Scale ◽  
Physical Processes ◽  
Scale Size ◽  
Mirror Mode ◽  
Energetic Particle Transport

Abstract. We discuss two different physical processes that create localized high β plasma regions. One is nonlinear wave-steepening, generating magnetic decreases (MDs) by a ponderomotive force. The other is the mirror instability generating alternating high and low β plasma regions. It is demonstrated that MDs and mirror modes are observationally quite different structures. MDs spatially occur in interplanetary space and mirror modes primarily in planetary magnetosheaths. MDs are characterized by: 1) variable (exponentially decreasing number with increasing) angular changes, 2) variable (exponentially decreasing) thicknesses, and 3) no characteristic inter-event spacings. In sharp contrast, mirror modes are characterized by: 1) little or no angular changes across the structures, 2) a characteristic scale size, and 3) are quasiperiodic in nature. Arguments are presented for the recently observed magnetic dips in the heliosheath being mirror mode structures. The sources of free energy for instability are discussed. Both structures are important for energetic particle transport in astrophysical and heliospheric plasmas.

Investigation of energy conversion processes and wave activity related to dipolarization fronts observed by MMS

2021 ◽  
Author(s):  
Soboh Alqeeq ◽  
Olivier Le Contel ◽  
Patrick Canu ◽  
Alessandro Retino ◽  
Thomas Chust ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Energy Flow ◽  
Poynting Vector ◽  
Wave Activity ◽  
Electromagnetic Energy ◽  
Particle Measurements ◽  
Dipolarization Front ◽  
The Earth ◽  
Current Densities ◽  
Scale Properties

<p>In the present work, we consider four dipolarization front (DF) events detected by MMS spacecraft in the Earth’s magnetotail during a substorm on 23rd of July 2017 between 16:05 and 17:19 UT. From their ion scale properties, we show that these four DF events embedded in fast Earthward plasma flows have classical signatures with increases of Bz, velocity and temperature and a decrease of density across the DF. We compute and compare current densities obtained from magnetic and particle measurements and analyse the Ohm’s law. Then we describe the wave activity related to these DFs. We investigate energy conversion processes via J.E calculations and estimate the importance of the electromagnetic energy flow by computing the divergence of the Poynting vector. Finally we discuss the electromagnetic energy conservation in the context of these DFs.</p>

scholarly journals Rippled Electron‐Scale Structure of a Dipolarization Front

2018 ◽  
Vol 45 (22) ◽  
pp. 12,116-12,124 ◽  
Author(s):  
Dong‐Xiao Pan ◽  
Yuri V. Khotyaintsev ◽  
Daniel B. Graham ◽  
Andris Vaivads ◽  
Xu‐Zhi Zhou ◽  
...  
Keyword(s):  
Scale Structure ◽  
Dipolarization Front

scholarly journals Modelling of mirror mode structures as propagating slow magnetosonic solitons

2009 ◽  
Vol 27 (12) ◽  
pp. 4379-4389 ◽  
Author(s):  
K. Stasiewicz ◽  
C. Z. Cheng
Keyword(s):  
Numerical Modelling ◽  
Excellent Agreement ◽  
Plasma Flow ◽  
Numerical Solutions ◽  
Small Subset ◽  
Instability Condition ◽  
Magnetic Pulsations ◽  
Fluid Theory ◽  
Mirror Mode ◽  
Two Fluid

Abstract. Cluster measurements in the magnetosheath with spacecraft separations of 2000 km indicate that magnetic pulsations interpreted as mirror mode structures are not frozen in plasma flow, but do propagate with speeds of up to ~50 km/s. Properties of these pulsations are shown to be consistent with propagating slow magnetosonic solitons. By using nonlinear two fluid theory we demonstrate that the well known classical mirror instability condition corresponds to a small subset in a continuum of exponentially varying solutions. With the measured plasma moments we have determined parameters of the polybaric pressure model in the region of occurrence of mirror type structures and applied it to numerical modelling of these structures. In individual cases we obtain excellent agreement between observed mirror mode structures and numerical solutions for magnetosonic solitons.

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