scholarly journals Delivery of cold, dense plasma sheet material into the near-Earth region

Author(s):  
M. F. Thomsen
Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 831
Author(s):  
Yue Yu ◽  
Zuzheng Chen ◽  
Fang Chen

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.


1997 ◽  
Vol 57 (1) ◽  
pp. 1-34 ◽  
Author(s):  
JOSEPH E. BOROVSKY ◽  
RICHARD C. ELPHIC ◽  
HERBERT O. FUNSTEN ◽  
MICHELLE F. THOMSEN

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.


2002 ◽  
Vol 30 (10) ◽  
pp. 2279-2288 ◽  
Author(s):  
M. Fujimoto ◽  
T. Mukai ◽  
S. Kokubun

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

2020 ◽  
Author(s):  
Lun Xie ◽  
Ying Xiong ◽  
Suiyan Fu ◽  
Zuyin Pu

<p>Electron pitch angle distribution (PAD) is a critical parameter in the study of the dynamics of the radiation belt electrons. It is well known that solar wind pressure has an impact on the PAD of the geomagnetically trapped electrons. Using the Van Allen Probes' data, we find that the MeV electron PAD at 4.5<L*<5.5 became narrowing (PAD is mainly concentrated at 90 degree) for over three days during a prolonged enhancement of the solar wind number density on November 27-30, 2015. During that period, the EMIC waves are observed by Van Allen Probe-A and ground stations on the afternoon and dusk MLTs at L>4. Meanwile, the precipitations of tens of keV protons and MeV electrons are observed by POES satellites. Additionally, there is a growing dip in electron phase space density at L*~5, indicating a local loss caused by the wave-particle interaction. The narrowing of the electron PAD is energy-dependent and the PAD is more anisotropic for electrons with higher energy, which is consistent with the wave-particle interaction with the EMIC waves. Furthermore, previous studies have shown that high solar wind density can lead to a hot and dense plasma sheet. The inward penetration of a dense plasma-sheet down to 4 Re has been confirmed by THEMIS spacecraft. We suggest that the overlap of the plasma sheet and the plasmasphere provide a favorable condition for exciting EMIC waves and the loss of small pitch angle electrons by EMIC waves can lead to the electron PAD narrowing. </p><div> </div>


2007 ◽  
Vol 34 (4) ◽  
Author(s):  
M. H. Denton ◽  
M. F. Thomsen ◽  
B. Lavraud ◽  
M. G. Henderson ◽  
R. M. Skoug ◽  
...  

2018 ◽  
Vol 123 (1) ◽  
pp. 464-472 ◽  
Author(s):  
Shichen Bai ◽  
Quanqi Shi ◽  
Anmin Tian ◽  
Motoharu Nowada ◽  
Alexander W. Degeling ◽  
...  

2015 ◽  
Vol 42 (19) ◽  
pp. 7867-7873 ◽  
Author(s):  
S. A. Fuselier ◽  
M. A. Dayeh ◽  
G. Livadiotis ◽  
D. J. McComas ◽  
K. Ogasawara ◽  
...  
Keyword(s):  

2018 ◽  
Vol 124 (5) ◽  
Author(s):  
Yan Peng ◽  
Binbin Qi ◽  
Xiankai Jiang ◽  
Zhi Zhu ◽  
Hongwei Zhao ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document