scholarly journals Energy limits of electron acceleration in the plasma sheet during substorms: A case study with the Magnetospheric Multiscale (MMS) mission

2016 ◽  
Vol 43 (15) ◽  
pp. 7785-7794 ◽  
Author(s):  
D. L. Turner ◽  
J. F. Fennell ◽  
J. B. Blake ◽  
J. H. Clemmons ◽  
B. H. Mauk ◽  
...  
Keyword(s):  
Plasma Sheet ◽  
Electron Acceleration ◽  
Magnetospheric Multiscale

scholarly journals The geometric factor of electrostatic plasma analyzers: A case study from the Fast Plasma Investigation for the Magnetospheric Multiscale mission

2012 ◽  
Vol 83 (3) ◽  
pp. 033303 ◽  
Author(s):  
Glyn A. Collinson ◽  
John C. Dorelli ◽  
Levon A. Avanov ◽  
Gethyn R. Lewis ◽  
Thomas E. Moore ◽  
...  
Keyword(s):  
Geometric Factor ◽  
Magnetospheric Multiscale ◽  
Magnetospheric Multiscale Mission ◽  
Plasma Investigation

scholarly journals On the alignment of velocity and magnetic fields within magnetosheath jets

2020 ◽  
Vol 38 (2) ◽  
pp. 287-296
Author(s):  
Ferdinand Plaschke ◽  
Maria Jernej ◽  
Heli Hietala ◽  
Laura Vuorinen
Keyword(s):  
Magnetic Fields ◽  
Entire Range ◽  
Dynamic Pressure ◽  
Bow Shock ◽  
Superposed Epoch Analysis ◽  
Magnetospheric Multiscale ◽  
Study Results ◽  
Epoch Analysis ◽  
The Magnetic Field

Abstract. Jets in the subsolar magnetosheath are localized enhancements in dynamic pressure that are able to propagate all the way from the bow shock to the magnetopause. Due to their excess velocity with respect to their environment, they push slower ambient plasma out of their way, creating a vortical plasma motion in and around them. Simulations and case study results suggest that jets also modify the magnetic field in the magnetosheath on their passage, aligning it more with their velocity. Based on Magnetospheric Multiscale (MMS) jet observations and corresponding superposed epoch analyses of the angles ϕ between the velocity and magnetic fields, we can confirm that this suggestion is correct. However, while the alignment is more significant for faster than for slower jets, and for jets observed close to the bow shock, the overall effect is small: typically, reductions in ϕ of around 10∘ are observed at jet core regions, where the jets' velocities are largest. Furthermore, time series of ϕ pertaining to individual jets significantly deviate from the superposed epoch analysis results. They usually exhibit large variations over the entire range of ϕ: 0 to 90∘. This variability is commonly somewhat larger within jets than outside them, masking the systematic decrease in ϕ at core regions of individual jets.

scholarly journals Cold and Dense Plasma Sheet Caused by Solar Wind Entry: Direct Evidence

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 831
Author(s):  
Yue Yu ◽  
Zuzheng Chen ◽  
Fang Chen
Keyword(s):  
Solar Wind ◽  
Plasma Sheet ◽  
Cross Correlation ◽  
Direct Evidence ◽  
Dense Plasma ◽  
Ion Density ◽  
Average Value ◽  
Magnetospheric Multiscale ◽  
Cross Correlation Analysis ◽  
Solar Wind Entry

We present a coordinated observation with the Magnetospheric Multiscale (MMS) mission, located in the Earth’s magnetotail plasma sheet, and the Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon’s Interaction with the Sun (ARTEMIS) mission, located in the solar wind, in order to understand the formation mechanism of the cold and dense plasma sheet (CDPS). MMS detected two CDPSs composed of two ion populations with different energies, where the energy of the cold ion population is the same as that of the solar wind measured by ARTEMIS. This feature directly indicates that the CDPSs are caused by the solar wind entry. In addition, He+ was observed in the CDPSs. The plasma density in these two CDPSs are ~1.8 cm−3 and ~10 cm−3, respectively, roughly 4–30 times the average value of a plasma sheet. We performed a cross-correlation analysis on the ion density of the CDPS and the solar wind, and we found that it takes 3.7–5.9 h for the solar wind to enter the plasma sheet. Such a coordinated observation confirms the previous speculation based on single-spacecraft measurements.

Plasma sheet oscillations and their relation to substorm development: Cluster and double star TC1 case study

2008 ◽  
Vol 41 (10) ◽  
pp. 1585-1592 ◽  
Author(s):  
T. Takada ◽  
R. Nakamura ◽  
Y. Asano ◽  
W. Baumjohann ◽  
A. Runov ◽  
...  
Keyword(s):  
Plasma Sheet ◽  
Double Star

scholarly journals The current sheet flapping motions induced by non-adiabatic ions: case study

2018 ◽  
Author(s):  
Xinhua Wei ◽  
Chunlin Cai ◽  
Henri Rème ◽  
Iannis Dandouras ◽  
George Parks
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Field Line ◽  
Magnetic Field Line ◽  
Plasma Sheet ◽  
Plasma Sources ◽  
Shear Structures ◽  
Particle Population ◽  
Alternating Bending

Abstract. In this paper, we analyzed the y-component of magnetic field line curvature in the plasma sheet and found that there are two kinds of shear structures of the flapping current sheet, i.e. symmetric and antisymmetric. The alternating bending orientations of guiding field are exactly corresponding to alternating north-south asymmetries of the bouncing ion population in the sheet center. Those alternating asymmetric plasma sources consequently induce the current sheet flapping motion as a driver. In addition, a substantial particle population with dawnward motion was observed in the center of a bifurcated current sheet. This population is identified as the quasi-adiabatic particles, and provides a net current opposite to the conventional cross-tail current.

scholarly journals Timescale for the formation of the cold-dense plasma sheet: A case study

2006 ◽  
Vol 33 (23) ◽  
Author(s):  
Simon Wing ◽  
Jay R. Johnson ◽  
Masaki Fujimoto
Keyword(s):  
Plasma Sheet ◽  
Dense Plasma

scholarly journals Roles of electrons and ions in formation of the current in mirror-mode structures in the terrestrial plasma sheet: Magnetospheric Multiscale observations

2020 ◽  
Vol 38 (2) ◽  
pp. 309-318 ◽  
Author(s):  
Guoqiang Wang ◽  
Tielong Zhang ◽  
Mingyu Wu ◽  
Daniel Schmid ◽  
Yufei Hao ◽  
...  
Keyword(s):  
Current Density ◽  
Plasma Sheet ◽  
Electron Velocity ◽  
Collective Behaviors ◽  
Ion Drift ◽  
Magnetospheric Multiscale ◽  
Electrons And Ions ◽  
Current Densities ◽  
Mirror Mode ◽  
Magnetospheric Multiscale Mission

Abstract. Mirror-mode structures widely exist in various space plasma environments. Here, we investigate a train of mirror-mode structures in the terrestrial plasma sheet on 11 August 2017 based on the Magnetospheric Multiscale mission. We find that bipolar current densities exist in the cross section of two hole-like mirror-mode structures, referred to as magnetic dips. The bipolar current density in the magnetic dip with a size of ∼2.2 ρi (the ion gyro radius) is mainly contributed by variations of the electron velocity, which is mainly formed by the magnetic gradient–curvature drift. For another magnetic dip with a size of ∼6.6 ρi, the bipolar current density is mainly caused by an ion bipolar velocity, which can be explained by the collective behaviors of the ion drift motions. The current density inside the mirror dip contributes to the maintenance of the hole-like structure's stable. Our observations suggest that the electrons and ions play different roles in the formation of currents in magnetic dips with different sizes.

scholarly journals Observations of plasma vortices in the vicinity of flow-braking: a case study

2009 ◽  
Vol 27 (8) ◽  
pp. 3009-3017 ◽  
Author(s):  
K. Keika ◽  
R. Nakamura ◽  
M. Volwerk ◽  
V. Angelopoulos ◽  
W. Baumjohann ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Plasma Sheet ◽  
Convective Flow ◽  
Flow Patterns ◽  
Plasma Flows ◽  
Convective Flows ◽  
Field Fluctuations ◽  
Plasma Vortices

Abstract. We examine fast plasma flows and magnetic field fluctuations observed by THEMIS at 03:00–03:30 UT on 12 December 2007. All THEMIS probes are situated in the near-Earth plasma sheet (XSM>−10 RE) with 1–2 RE spacecraft separations in azimuthal and radial directions. We focus on the observations of plasma convective flows made simultaneously by more than one THEMIS probe. At about 03:10 UT and 03:14 UT, the THEMIS P2 probe observed earthward flows of >100 km/s. The THEMIS P1 probe, located duskward and earthward of P2, observed tailward flows under a positive Bz. The inner most probe THEMIS P4, located at almost the same MLT as THEMIS P1 and P2, did not see any clear flow. We examine the convective flow patterns for the THEMIS observations. We conclude that plasma vortices are formed near the region where the earthward flows slow down and turn in azimuthal directions.

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