scholarly journals Contribution of charge exchange loss to the storm time ring current decay: IMAGE/HENA observations

2006 ◽  
Vol 111 (A11) ◽  
Author(s):  
K. Keika ◽  
M. Nosé ◽  
P. C. Brandt ◽  
S. Ohtani ◽  
D. G. Mitchell ◽  
...  
Keyword(s):  
Charge Exchange ◽  
Ring Current ◽  
Current Decay

MLT Dependence of Contribution of Charge Exchange Loss to the Storm Time Ring Current Decay: Van Allen Probes Observations

2020 ◽  
Author(s):  
Songyan Li ◽  
Hao Luo
Keyword(s):  
Charge Exchange ◽  
Ring Current ◽  
Radial Distance ◽  
Recovery Phase ◽  
Local Times ◽  
Loss Mechanism ◽  
Exchange Effect ◽  
Current Decay ◽  
Van Allen Probes ◽  
Level 3

<p>Much evidence has indicated that charge exchange with the neutral atoms is an important loss mechanism of the ring current ions, especially during the slow recovery phase of a geomagnetic storm. Most of the studies, however, were focused on the global effect of the charge exchange on the ring current decay. The effect on different magnetic local times and L shells has not been achieved. In this study, based on the in-situ energetic ion data (Level 3) from RBSPICE onboard two Van Allen Probes, we study the contribution of the charge exchange, calculated from the differential flux of ions, to the local ring current decay at different magnetic local times and radial distance. Results indicate that the charge exchange effect on the ring current decay shows clear MLT and L dependence. Our study provides important information of spatial distribution of the ring current loss evolution, which could be as a reference during the ring current modeling.</p>

Ring current decay during storm recover phase: RBSP Observation

2020 ◽  
Author(s):  
Ao Chen ◽  
Chao Yue ◽  
Hongfei Chen ◽  
Qiugang Zong
Keyword(s):  
Charge Exchange ◽  
Ring Current ◽  
Current System ◽  
Charged Particles ◽  
Oxygen Ions ◽  
Current Decay ◽  
The Earth ◽  
Comparison Results ◽  
Wide Energy ◽  
Fitting In

<p>Ring curent is an important current system in the Earth's magnetosphere. Many charged particles, especially protons and oxygen ions, move around the Earth due to due to electromagnetic drifts, which forms the ring current. During the main phase of a magnetic storm, ring current will grow stronger while it will decay slowly during recover phase. It is thought that charge exchange is the main mechanism of ring current decay [Daglis et al., 1999]. Hereby we use charge exchange theories to calculate charge exchange lifetimes of protons and oxygen ions during recover phase of many storms. Meanwhile, data of RBSP has been used for fitting in order to get real lifetimes of  protons and oxygen ions. We compared the observed lifetimes with the theory prediction and find that  a. the two are close at high L(>4) values and low energy(<55keV) for protons, b. the two are similar in a wide energy(1~600keV) range but a relatively narrow L(different at different energies) range, c. day or night make little difference on the comparison results.</p>

scholarly journals Another way of deriving the ring current decay time during disturbed periods

1995 ◽  
Vol 38 (2) ◽  
Author(s):  
M. M. Zossi de Artigas ◽  
J. R. Manzano
Keyword(s):  
Ring Current ◽  
Coupling Parameter ◽  
Life Time ◽  
Recovery Phase ◽  
Main Phase ◽  
Physical Analysis ◽  
Inner Magnetosphere ◽  
Current Decay ◽  
The Many ◽  
Energy Dissipated

Coupling parameter, E, and the total energy dissipated by the magnetosphere, UT, are determined for six disturbed periods, following three known criteria for UT computation. It is observed that UT exceeds E for Dst < -90 nT, for alI models. Differences between models reside on the estimated valnes for the particles' life time il1 the equatorial ring current. The values of TR, used in the models, are small during the main phase of the di."turbance, in disagreement with the charge exchange life time of the majority species, H+ and O'-. Based on this conclusion, a different criterion to calculate TR is proposed, differentiating the different stages of the perturbation. TR is calculated, for the main phase of the storm, from the rate of energy deposition estimation, Q, in the ring current. For Dst recovery phase, the vallles are obtained from a ring current decay law computation. The UTvu calculated, physically more coherent with the processes occurring during the event, is now smaller than expected. In this sense, it is understood that the power generated by the solar wind-magnetosphere dy- namo, should also be distributed in the inner magnetosphere, auroral zones and equatorial ring current, as in the outer magnetosphere, plasmoids in the tail shot in antisolar direction. A further adjustment of E, with the Chapman-Ferraro distance, 10' variable, has been made. Although the reslllts, improve the estimation of E, they are sti!l smaller than UT, except UTNU, for some disturbed periods. This result indicates the uncertainty in the computation of the input energy, by using the many expressions proposed in the literature, which are always presented as laws proportional to a given group of parameters, with an unknown factor of proportionality, which deserves more detailed physical analysis.

Ring current decay

2020 ◽  
pp. 181-223
Author(s):  
Vania K. Jordanova
Keyword(s):  
Ring Current ◽  
Current Decay

scholarly journals Inference of the ring current ion composition by means of charge exchange decay

1981 ◽  
Vol 86 (A5) ◽  
pp. 3470 ◽  
Author(s):  
Paul H. Smith ◽  
N. K. Bewtra ◽  
R. A. Hoffman
Keyword(s):  
Charge Exchange ◽  
Ring Current ◽  
Ion Composition
Sign in / Sign up

Export Citation Format

Share Document