Transport of plasma sheet material to the inner magnetosphere

2007 ◽  
Vol 34 (4) ◽  
Author(s):  
M. H. Denton ◽  
M. F. Thomsen ◽  
B. Lavraud ◽  
M. G. Henderson ◽  
R. M. Skoug ◽  
...  
Keyword(s):  
Plasma Sheet ◽  
Sheet Material ◽  
Inner Magnetosphere

Access of plasma sheet ions to the inner magnetosphere

2001 ◽  
Author(s):  
Paul Rothwell ◽  
William Burke ◽  
Carl-Gunne Falthammar
Keyword(s):  
Plasma Sheet ◽  
Inner Magnetosphere

Response of the inner magnetosphere and the plasma sheet to a sudden impulse

2008 ◽  
Vol 113 (A7) ◽  
pp. n/a-n/a ◽  
Author(s):  
K. Keika ◽  
R. Nakamura ◽  
W. Baumjohann ◽  
A. Runov ◽  
T. Takada ◽  
...  
Keyword(s):  
Plasma Sheet ◽  
Inner Magnetosphere ◽  
Sudden Impulse

scholarly journals Strong Southward and Northward Currents Observed in the Inner Plasma Sheet

2019 ◽  
Author(s):  
Yanyan Yang ◽  
Chao Shen ◽  
Yong Ji
Keyword(s):  
Magnetic Field ◽  
Plasma Sheet ◽  
Ring Current ◽  
Generation Mechanism ◽  
Storm Events ◽  
Current Generation ◽  
Inner Magnetosphere ◽  
Latitude Region ◽  
Field Lines ◽  
The Magnetic Field

Abstract. It is generally believed that field aligned currents (FACs) and the ring current (RC) are two dominant parts of the inner magnetosphere. However, using the Cluster spacecraft crossing of the pre-midnight inner plasma sheet in the latitude region between 10° N and 30° N, it is found that, during large storm events, in addition to FACs and the RC, there also exist strong southward and northward currents, which cannot be FACs, because the magnetic field in these regions is mainly along the XY plane. Detailed investigation shows that both magnetic field lines (MFLs) and currents in these regions highly fluctuate. When the curvature of MFLs changes direction in the XY plane, the current also alternatively switches between southward and northward. Further analysis of the current generation mechanism indicates that the most reasonable candidate for the origin of these southward and northward currents is the curvature drift of energetic particles.

scholarly journals Magnetic dipolarizations inside geosynchronous orbit with tailward ion flows

2019 ◽  
Vol 37 (3) ◽  
pp. 289-297 ◽  
Author(s):  
Xiaoying Sun ◽  
Weining William Liu ◽  
Suping Duan
Keyword(s):  
Plasma Sheet ◽  
Sharp Increase ◽  
Energetic Electron ◽  
Elevation Angle ◽  
Time History ◽  
Geosynchronous Orbit ◽  
Inner Magnetosphere ◽  
Transfer Path ◽  
New Energy ◽  
History Of

Abstract. Electromagnetic field and plasma data from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) near-Earth probes are used to investigate magnetic dipolarizations inside geosynchronous orbit on 27 August 2014 during an intense substorm with AEmax∼1000 nT. THEMIS-D (TH-D) was located inside geosynchronous orbit around midnight in the interval from 09:25 to 09:55 UT. During this period, two distinct magnetic dipolarizations with tailward ion flows are observed by TH-D. The first one is indicated by the magnetic elevation angle increase from 15 to 25∘ around 09:30:40 UT. The tailward perpendicular velocity is V⊥x∼-50 km s−1. The second one is presented by the elevation angle increase from 25 to 45∘ around 09:36 UT, and the tailward perpendicular velocity is V⊥x∼-70 km s−1. These two significant dipolarizations are accompanied with the sharp increase in the energy flux of energetic electron inside geosynchronous orbit. After a 5 min expansion of the near-Earth plasma sheet (NEPS), THEMIS-E (TH-E) located outside geosynchronous orbit also detected this tailward expanding plasma sheet with ion flows of −150 km s−1. The dipolarization propagates tailward with a speed of −47 km s−1 along a 2.2 RE distance in the X direction between TH-D and TH-E within 5 min. These dipolarizations with tailward ion flows observed inside geosynchronous orbit indicate a new energy transfer path in the inner magnetosphere during substorms.

The Earth's plasma sheet as a laboratory for flow turbulence in high-β MHD

1997 ◽  
Vol 57 (1) ◽  
pp. 1-34 ◽  
Author(s):  
JOSEPH E. BOROVSKY ◽  
RICHARD C. ELPHIC ◽  
HERBERT O. FUNSTEN ◽  
MICHELLE F. THOMSEN
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Plasma Sheet ◽  
Sheet Material ◽  
Single Point ◽  
Power Laws ◽  
Fluxgate Magnetometer ◽  
Flow Measurements ◽  
Field Fluctuations ◽  
Flow Velocities

The bulk flows and magnetic-field fluctuations of the plasma sheet are investigated using single-point measurements from the ISEE-2 Fast Plasma Experiment and fluxgate magnetometer. Ten several-hour-long intervals of continuous data (with 3 s and 12 s time resolution) are analysed. The plasma-sheet flow appears to be strongly ‘turbulent’ (i.e. the flow is dominated by fluctuations that are unpredictable, with rms velocities[Gt ]mean velocities and with field fluctuations≈mean fields). The flow velocities are typically sub-Alfvénic. The flow-velocity probability distribution P(v) is constructed, and is found to be well fitted by exponential functions. Autocorrelation functions [Ascr ](τ) are constructed, and the autocorrelation times τcorr for the flow velocities are found to be about 2 min. From the flow measurements, an estimate of the mixing length in the plasma sheet is produced, yielding Lmix≈2 Earth radii; correspondingly, the plasma-sheet material appears to be well mixed in density and temperature. An eddy viscosity for the plasma sheet is also estimated. Power spectra, which are constructed from the v(t) and B(t) time series, have portions that are power laws with spectral indices that are near the range of those expected for turbulence theories. The plasma sheet may provide a laboratory for the study of turbulence in parameter regimes different from that of solar-wind turbulence: the plasma sheet is a β[Gt ]1, hot-ion plasma, and the turbulence may be strongly driven rather than well developed. The turbulent nature of the flow and the disordered nature of the magnetic field have implications for the transport of plasma-sheet material, for the penetration of the solar-wind electric field into the plasma sheet, and for the calculation of particle orbits in the magnetotail.

Effects of spatial diffusion in the inner plasma sheet and the structure of the diffusion tensor

1995 ◽  
Vol 13 (2) ◽  
pp. 111-117 ◽  
Author(s):  
V. E. Zakharov ◽  
M. I. Pudovkin
Keyword(s):  
Flux Tube ◽  
Plasma Sheet ◽  
Diffusion Tensor ◽  
Plasma Pressure ◽  
Spatial Diffusion ◽  
Angle Distribution ◽  
Inner Magnetosphere ◽  
Electron Population ◽  
Magnetospheric Convection ◽  
Isotropic Pitch

Abstract. A standard pair of equations is used to describe the behaviour of a single monoenergetic particle (proton or electron) population on a geomagnetic flux tube drifting in the magnetosphere. When particle losses from the drifting flux tube into the ionosphere are neglected, this behaviour is adiabatic in a thermodynamic sense. For a population of particles with an isotropic pitch-angle distribution, the generalization of that system of equations is obtained by adding radial and azimuthal spatial diffusion terms. The magnetic field is taken to be dipolar in the inner magnetosphere. The potential electric field is assumed to consist of magnetospheric convection and corotation components. Experimental data are used to estimate the radial equatorial profiles of the plasma sheet pressure. Assuming that the local time and L-shell variations are separable and supposing steady-state conditions, the expressions for the diffusion tensor components are evaluated. The influence of spatial diffusion on the radial and azimuthal profiles of the plasma pressure in the inner plasma sheet is also discussed.

Interplay of bubble injections in the plasma sheet dynamics as inferred from RCM-I simulations

2020 ◽  
Author(s):  
Sina Sadeghzadeh ◽  
Jian Yang
Keyword(s):  
Plasma Sheet ◽  
High Speed ◽  
Space Environment ◽  
Inner Magnetosphere ◽  
Near Earth Space ◽  
Hot Plasma ◽  
Plasma Distribution ◽  
Rice Convection Model ◽  
Convection Model ◽  
Interchange Instability

<p><span>Understanding the transport of hot plasma from tail towards the inner magnetosphere is of great importance to improve our perception of the near-Earth space environment. In accordance with the recent observations, the contribution of bursty bulk flows (BBFs)/bubbles in the inner plasma sheet especially in the storm-time ring current formation is nonnegligible. These high-speed plasma flows with depleted flux tube/entropy are likely formed in the mid tail due to magnetic reconnection and injected earthward as a result of interchange instability. In this presentation, we investigate the interplay of these meso-scale structures on the average magnetic field and plasma distribution in various regions of the plasma sheet, using the Inertialized Rice Convection Model (RCM-I). We will discuss the comparison of our simulation results with the observational statistics and data-based empirical models.</span></p>

Cold-dense plasma sheet and hot-dense ions in the inner-magnetosphere

2002 ◽  
Vol 30 (10) ◽  
pp. 2279-2288 ◽  
Author(s):  
M. Fujimoto ◽  
T. Mukai ◽  
S. Kokubun
Keyword(s):  
Plasma Sheet ◽  
Dense Plasma ◽  
Inner Magnetosphere
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