Measurements of convection electric field in the inner magnetosphere

2018 ◽  
Vol 61 (12) ◽  
pp. 1866-1871
Author(s):  
Xin Lv ◽  
WenLong Liu
Keyword(s):  
Electric Field ◽  
Inner Magnetosphere ◽  
Convection Electric Field

scholarly journals Magnetospheric convection electric field dynamics andstormtime particle energization: case study of the magneticstorm of 4 May 1998

2004 ◽  
Vol 22 (2) ◽  
pp. 497-510 ◽  
Author(s):  
G. V. Khazanov ◽  
M. W. Liemohn ◽  
T. S. Newman ◽  
M.-C. Fok ◽  
A. J. Ridley
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Transport Model ◽  
Storm Event ◽  
Inner Magnetosphere ◽  
Narrow Channels ◽  
Near Earth Space ◽  
Magnetospheric Convection ◽  
Convection Electric Field ◽  
Seed Population

Abstract. It is shown that narrow channels of high electric field are an effective mechanism for injecting plasma into the inner magnetosphere. Analytical expressions for the electric field cannot produce these channels of intense plasma flow, and thus, result in less entry and adiabatic energization of the plasma sheet into near-Earth space. For the ions, omission of these channels leads to an underprediction of the strength of the stormtime ring current and therefore, an underestimation of the geoeffectiveness of the storm event. For the electrons, omission of these channels leads to the inability to create a seed population of 10-100 keV electrons deep in the inner magnetosphere. These electrons can eventually be accelerated into MeV radiation belt particles. To examine this, the 1-7 May 1998 magnetic storm is studied with a plasma transport model by using three different convection electric field models: Volland-Stern, Weimer, and AMIE. It is found that the AMIE model can produce particle fluxes that are several orders of magnitude higher in the L = 2 – 4 range of the inner magnetosphere, even for a similar total cross-tail potential difference. Key words. Space plasma physics (charged particle motion and acceleration) – Magnetospheric physics (electric fields, storms and substorms)

scholarly journals Multiple discrete-energy ion features in the inner magnetosphere: 9 February 1998, event

2004 ◽  
Vol 22 (4) ◽  
pp. 1297-1304 ◽  
Author(s):  
Y. Ebihara ◽  
M. Ejiri ◽  
H. Nilsson ◽  
I. Sandahl ◽  
M. Grande ◽  
...  
Keyword(s):  
Distribution Function ◽  
Electric Field ◽  
Realistic Model ◽  
Particle Simulation ◽  
Discrete Energy ◽  
Particle Tracing ◽  
Inner Magnetosphere ◽  
Convection Electric Field ◽  
Dipole Magnetic Field ◽  
Polar Satellite

Abstract. Multiple discrete-energy ion bands observed by the Polar satellite in the inner magnetosphere on 9 February 1998 were investigated by means of particle simulation with a realistic model of the convection electric field. The multiple bands appeared in the energy vs. L spectrum in the 1–100 keV range when Polar traveled in the heart of the ring current along the outbound and inbound paths. We performed particle tracing, and simulated the energy vs. L spectra of proton fluxes under the dipole magnetic field, the corotation electric field, and the realistic convection electric field model with its parameters depending on the solar wind data. Simulated spectra are shown to agree well with the observed ones. A better agreement is achieved when we rotate the convection electric potential eastward by 2h inMLT and we change the distribution function in time in the near-Earth magnetotail. It is concluded that the multiple bands are likely produced by two processes for this particular event, that is, changes in the convection electric field (for >3keV protons) and changes in the distribution function in the near-Earth magnetotail (for <3keV protons). Key words. Magnetospheric physics (energetic particles, trapped; electric field) – Space plasma physics (numerical simulation studies)

scholarly journals Global estimates of plasmaspheric losses during moderate disturbance intervals

2010 ◽  
Vol 28 (1) ◽  
pp. 27-36 ◽  
Author(s):  
M. Spasojevic ◽  
B. R. Sandel
Keyword(s):  
Solar Wind ◽  
Electric Field ◽  
Boundary Layers ◽  
Total Mass ◽  
Density Ratio ◽  
Individual Case ◽  
Number Density ◽  
Inner Magnetosphere ◽  
Moderate Disturbance ◽  
Global Estimates

Abstract. For a set of five moderate disturbance events, we calculate the total number of He+ ions removed the plasmasphere using calibrated global EUV images. In each of the events, between ~0.6 and 2.2×1030 He+ ions are removed from a region of the inner magnetosphere from L=1.5 to 5.5. This loss constitutes between 20% and 42% of the initial He+ distribution. The lost percentage is correlated with the number of hours of strongly positive solar wind electric field (Ey>2.5 mV/m). Also, the total amount of material removed from the plasmasphere is estimated by using several values of the He+ to H+ number density ratio. The total mass lost is found to be in the range of 20 to 80 metric tons although for each individual case the estimate can vary by over 50% depending on assumed density ratio. We also attempt to distinguish between losses to the ionosphere and losses to the dayside boundary layers by estimating losses interior and exterior to the newly formed plasmapause boundary. For the events studied, losses inside the new plasmapause constitute between 24% to 54% of the total number of He+ ions lost.

scholarly journals Analyzing electric field morphology through data-model comparisons of the Geospace Environment Modeling Inner Magnetosphere/Storm Assessment Challenge events

2006 ◽  
Vol 111 (A11) ◽  
Author(s):  
Michael W. Liemohn ◽  
Aaron J. Ridley ◽  
Janet U. Kozyra ◽  
Dennis L. Gallagher ◽  
Michelle F. Thomsen ◽  
...  
Keyword(s):  
Electric Field ◽  
Data Model ◽  
Environment Modeling ◽  
Inner Magnetosphere ◽  
Model Comparisons

scholarly journals Energetic ion injection and formation of the storm-time symmetric ring current

2006 ◽  
Vol 24 (12) ◽  
pp. 3547-3556 ◽  
Author(s):  
L. Xie ◽  
Z. Y. Pu ◽  
X. Z. Zhou ◽  
S. Y. Fu ◽  
Q.-G. Zong ◽  
...  
Keyword(s):  
Electric Field ◽  
Ring Current ◽  
Particle Trajectory ◽  
Three Dimensional ◽  
Extensive Study ◽  
Current Injection ◽  
Ion Injection ◽  
Convection Electric Field ◽  
Trajectory Calculations ◽  
Current Region

Abstract. An extensive study of ring current injection and intensification of the storm-time ring current is conducted with three-dimensional (3-D) test particle trajectory calculations (TPTCs). The TPTCs reveal more accurately the process of ring current injection, with the main results being the following: (1) an intense convection electric field can effectively energize and inject plasma sheet particles into the ring current region within 1–3 h. (2) Injected ions often follow chaotic trajectories in non-adiabatic regions, which may have implications in storm and ring current physics. (3) The shielding electric field, which arises as a consequence of enhanced convection and co-exists with the injection and convection electric field, may cause the original open trajectories of injected ions with higher energy to change into closed ones, thus playing a role in the formation of the symmetric ring current.

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