Ring current ion flows and convection electric field as expected from observations by SAC-B/ISENA

1996 ◽  
Vol 23 (23) ◽  
pp. 3285-3288 ◽  
Author(s):  
A. Milillo ◽  
S. Orsini ◽  
I. A. Daglis ◽  
M. Candidi
2006 ◽  
Vol 24 (12) ◽  
pp. 3547-3556 ◽  
Author(s):  
L. Xie ◽  
Z. Y. Pu ◽  
X. Z. Zhou ◽  
S. Y. Fu ◽  
Q.-G. Zong ◽  
...  

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.


2002 ◽  
Vol 29 (9) ◽  
pp. 62-1-62-4 ◽  
Author(s):  
M. W. Liemohn ◽  
J. U. Kozyra ◽  
M. R. Hairston ◽  
D. R. Weimer ◽  
G. Lu ◽  
...  

2004 ◽  
Vol 22 (2) ◽  
pp. 497-510 ◽  
Author(s):  
G. V. Khazanov ◽  
M. W. Liemohn ◽  
T. S. Newman ◽  
M.-C. Fok ◽  
A. J. Ridley

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)


1977 ◽  
Vol 55 (3) ◽  
pp. 530-535 ◽  
Author(s):  
Robert H. Kohler ◽  
William F. Reynolds

Correlations of cyclopropyl proton chemical shifts for 4-substituted (2,2-dichlorocyclopropyl)-benzenes with σI and σR0 provide evidence that these chemical shifts reflect direct field effects and weak phenyl–cyclopropyl conjugative interactions. Corrections for variable ring current effects due to substituent-induced changes in conformation improve the individual correlations but do not alter the basic pattern of results. Correlation of the β cyclopropyl 1H chemical shift difference with σI with calculated hydrogen electron densities, and with calculated electric field components provides further strong evidence for a field effect on 1H chemical shifts.


2015 ◽  
Vol 33 (8) ◽  
pp. 965-982 ◽  
Author(s):  
M. W. Liemohn ◽  
R. M. Katus ◽  
R. Ilie

Abstract. Currents from the Hot Electron and Ion Drift Integrator (HEIDI) inner magnetospheric model results for all of the 90 intense storms (disturbance storm-time (Dst) minimum < −100 nT) from solar cycle 23 (1996–2005) are calculated, presented, and analyzed. We have categorized these currents into the various systems that exist in near-Earth space, specifically the eastward and westward symmetric ring current, the partial ring current, the banana current, and the tail current. The current results from each run set are combined by a normalized superposed epoch analysis technique that scales the timeline of each phase of each storm before summing the results. It is found that there is a systematic ordering to the current systems, with the asymmetric current systems peaking during storm main phase (tail current rising first, then the banana current, followed by the partial ring current) and the symmetric current systems peaking during the early recovery phase (westward and eastward symmetric ring current having simultaneous maxima). The median and mean peak amplitudes for the current systems ranged from 1 to 3 MA, depending on the setup configuration used in HEIDI, except for the eastward symmetric ring current, for which the mean never exceeded 0.3 MA for any HEIDI setup. The self-consistent electric field description in HEIDI yielded larger tail and banana currents than the Volland–Stern electric field, while the partial and symmetric ring currents had similar peak values between the two applied electric field models.


Sign in / Sign up

Export Citation Format

Share Document