Multi‐Event Studies of Sudden Energetic Electron Enhancements in the Inner Magnetosphere and Its Association with Plasmapause Positions

2021 ◽  
Author(s):  
L.‐Y. Khoo ◽  
X. Li ◽  
H. Zhao ◽  
S. A. Thaller ◽  
B. Hogan
Keyword(s):  
Energetic Electron ◽  
Event Studies ◽  
Inner Magnetosphere

scholarly journals Observation of reconnection pulses by Cluster and Double Star

2005 ◽  
Vol 23 (8) ◽  
pp. 2921-2927 ◽  
Author(s):  
X. H. Deng ◽  
R. X. Tang ◽  
R. Nakamura ◽  
W. Baumjohann ◽  
T. L. Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energetic Electron ◽  
Curvature Vector ◽  
Double Star ◽  
Neutral Sheet ◽  
Inner Magnetosphere ◽  
Point Analysis ◽  
Earthward Flow ◽  
Tailward Flow ◽  
The Magnetic Field

Abstract. During a reconnection event on 7 August 2004, Cluster and Double Star (TC-1) were near the neutral sheet and simultaneously detected the signatures of the reconnection pulses. AT 22:59 UT tailward flow followed by earthward flow was detected by Cluster at about 15 RE, while earthward plasma flow followed by tailward flow was observed by TC-1 at about 10 RE. During the flow reversal from tailward to earthward, the magnetic field Bz changed sign from mainly negative values to positive, and the X component of the magnetic curvature vector switched sign from the tailward direction to the earthward direction, which indicates that the reconnection site (X-line) moved tailward past the Cluster constellation. By using multi-point analysis and observation of energetic electron and ion flux, we study the movement and structure of the current sheet and discuss the braking effect of the earthward flow bursts in the inner magnetosphere.

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.

scholarly journals Energetic Electron Injections Deep Into the Inner Magnetosphere: A Result of the Subauroral Polarization Stream (SAPS) Potential Drop

2018 ◽  
Vol 45 (9) ◽  
pp. 3811-3819 ◽  
Author(s):  
Solène Lejosne ◽  
B. S. R. Kunduri ◽  
F. S. Mozer ◽  
D. L. Turner
Keyword(s):  
Energetic Electron ◽  
Potential Drop ◽  
Inner Magnetosphere

Statistical Distribution of Bifurcation of Earth's Inner Energetic Electron Belt at tens of keV

2021 ◽  
Author(s):  
Man Hua ◽  
Binbin Ni ◽  
Wen Li ◽  
Qianli Ma ◽  
Xudong Gu ◽  
...  
Keyword(s):  
Electron Energy ◽  
Energetic Electron ◽  
Low Frequency ◽  
Inner Magnetosphere ◽  
Near Earth Space ◽  
Naturally Occurring ◽  
Van Allen Probes ◽  
Radial Structure ◽  
Hemisphere Winter

<p>The Earth’s inner energetic electron belt typically exhibits one-peak radial structure with high flux intensities at radial distances < ~2.5 Earth radii. Recent studies suggested that human-made very-low-frequency (VLF) transmitters leaked into the inner magnetosphere can efficiently scatter energetic electrons, bifurcating the inner electron belt. In this study, we use 6-year electron flux data from Van Allen Probes to comprehensively analyze the statistical distributions of the bifurcated inner electron belt and their dependence on electron energy, season, and geomagnetic activity, which is crucial to understand when and where VLF transmitters can efficiently scatter electrons in addition to other naturally occurring waves. We reveal that bifurcation can be frequently observed for tens of keV electrons under relatively quiet geomagnetic conditions, typically after significant flux enhancements that elevate fluxes at L = 2.0 – ~2.5 providing the prerequisite for the bifurcation. The bifurcation typically lasts for a few days until interrupted by substorm injections or inward radial diffusion. The L-shells of bifurcation dip decrease with increasing electron energy, and the occurrence of bifurcation is higher during northern hemisphere winter than summer, supporting the important role of VLF transmitter waves in energetic electron loss in near-Earth space.</p>

Energetic electron injections deep into the inner magnetosphere associated with substorm activity

2015 ◽  
Vol 42 (7) ◽  
pp. 2079-2087 ◽  
Author(s):  
D. L. Turner ◽  
S. G. Claudepierre ◽  
J. F. Fennell ◽  
T. P. O'Brien ◽  
J. B. Blake ◽  
...  
Keyword(s):  
Energetic Electron ◽  
Inner Magnetosphere ◽  
Substorm Activity

scholarly journals MDS-1 Observations of Highly Energetic Electron Environment in the Inner Magnetosphere

2009 ◽  
Vol 7 (ists26) ◽  
pp. Tr_2_11-Tr_2_14 ◽  
Author(s):  
Takahiro OBARA ◽  
Haruhisa MATSUMOTO ◽  
Kiyokazu KOGA ◽  
Hideki KOSHIISHI ◽  
Tateo GOKA
Keyword(s):  
Energetic Electron ◽  
Inner Magnetosphere

Statistical Distribution of Energetic Electron Precipitation due to Hiss Waves In the Earth’s Inner Magnetosphere

2021 ◽  
Author(s):  
Qianli Ma
Keyword(s):  
Energy Flux ◽  
Pitch Angle ◽  
Energetic Electron ◽  
Statistical Distribution ◽  
Electron Precipitation ◽  
Characteristic Energy ◽  
Loss Cone ◽  
Inner Magnetosphere ◽  
The Earth ◽  
Chorus Waves

<p>We investigate the statistical distribution of energetic electron precipitation from the equatorial magnetosphere due to hiss waves in the plasmasphere and plumes. Using Van Allen Probes measurements, we calculate the pitch angle diffusion coefficients at the pitch angle of bounce loss cone, and evaluate the energy spectrum of precipitating electron flux using quasi-linear theory. Our ~6.5 years survey shows that, during disturbed times, the plasmaspheric hiss mostly causes the electron precipitation at L > 3 near the dayside in the plasmasphere, and hiss waves in plume cause the precipitation at L > 5 near dayside and L > 3.5 near the dusk side. The precipitating energy flux increases with increasing geomagnetic index, and is typically higher in the plasmaspheric plume than the plasmasphere. The characteristic energy of precipitation increases from ~20 keV at L = 6 to ~100 keV at L = 3, potentially causing the loss of electrons at several hundred keV. Although the total precipitating energy flux due to hiss waves is generally lower than the precipitation due to whistler mode chorus waves, the characteristic energy of precipitation due to hiss is higher, and the precipitation extends closer to the Earth.</p>

Energetic electron injections into the inner magnetosphere during the Jan. 10-11, 1997 magnetic storm

1998 ◽  
Vol 25 (14) ◽  
pp. 2561-2564 ◽  
Author(s):  
Xinlin Li ◽  
D. N. Baker ◽  
M. Temerin ◽  
T. Cayton ◽  
G. D. Reeves ◽  
...  
Keyword(s):  
Magnetic Storm ◽  
Energetic Electron ◽  
Inner Magnetosphere

scholarly journals Magnetic dipolarizations inside geosynchronous orbit with tailward ions flow

2018 ◽  
Author(s):  
Xiaoying Sun ◽  
Weining William Liu ◽  
Suping Duan
Keyword(s):  
Plasma Sheet ◽  
Energetic Electron ◽  
Elevation Angle ◽  
Time History ◽  
Geosynchronous Orbit ◽  
Inner Magnetosphere ◽  
Ion Flow ◽  
Transfer Path ◽  
New Energy ◽  
History Of

Abstract. Electromagnetic field and plasma data from the Time History of Events and Macroscale Interactions duringSubstorms (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 UT to 09:55 UT. During this period two distinct magnetic dipolarizations with tailward ions flow are observed by TH-D. The first one is displayed by magnetic elevation angle increase from 15 degree to 25 degree around 09:30:40 UT. The tailward perpendicular velocity is V⟂x ~ −50 km/s. The second one is presented by the elevation angle increase from 25 degree to 45 degree around 09:36 UT. And the tailward perpendicular velocity is V⟂x ~ −70 km/s. These two significant dipolarizations are accompanied with the sharp increase in the energy flux of energetic electron inside geosynchronous. After 5 min expanding of near-Earth plasma sheet (NEPS), THEMIS-E (TH-E) located outside geosynchronous orbit also detects this tailward expanding plasma sheet with ion flow −150 km/s. The dipolarization propagates tailward with speed −47 km/s, along 2.2 RE distance in the X direction between TH-D and TH-E within 5 min. These dipolarizations with tailward ions flow observed inside geosynchronous orbit indicate new energy transfer path in the inner magnetosphere during substorms.

The Inner Magnetosphere Imager mission

1993 ◽  
Author(s):  
Les Johnson ◽  
Melody Herrmann
Keyword(s):  
Inner Magnetosphere
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