Effects of the Ring Current Decay Rate on the Energy State of the Magnetosphere

2010 ◽  
Vol 53 (3) ◽  
pp. 329-338 ◽  
Author(s):  
Wen-Yao XU ◽  
Ai-Min DU
Keyword(s):  
Decay Rate ◽  
Ring Current ◽  
Energy State ◽  
Current Decay

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

Energy dissipation during a small substorm

1995 ◽  
Vol 13 (5) ◽  
pp. 494-504 ◽  
Author(s):  
A. Belehaki ◽  
H. Mavromichalaki ◽  
D. V. Sarafopoulos ◽  
E. T. Sarris
Keyword(s):  
Solar Wind ◽  
Energy Dissipation ◽  
Wind Energy ◽  
Growth Phase ◽  
Ring Current ◽  
Interplanetary Medium ◽  
Energy State ◽  
Expansion Phase ◽  
Driven System ◽  
Solar Wind Energy

Abstract. The relative importance of the two most likely modes of input energy dissipation during the substorm of 8 May 1986, with an onset at 12:15 UT (CDAW 9E event), is examined here. The combination of data from the interplanetary medium, the magnetotail and the ground allowed us, first of all, to establish the sequence of phenomena which compose this substorm. In order to calculate the magnetospheric energetics we have improved the Akasofu model, by adding two more terms for the total magnetospheric output energy. The first one represents the energy consumed for the substorm current wedge transformation, supplied by the asymmetric ring current. This was found to be 39% of the solar wind energy entering the magnetosphere from the start of the growth phase up to the end of the expansion phase. The second term represents the energy stored in the tail or returned to the solar wind. Our results suggest that the substorm leaves the magnetosphere in a lower energy state, since, according to our calculations, 23% of the energy that entered the magnetosphere during the whole disturbance was returned back to the solar wind. Finally, it is interesting to note that during the growth phase the driven system grow considerably, consuming 36% of the solar wind energy which entered the magnetosphere during this early phase of the substorm.

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

&lt;p&gt;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.&lt;/p&gt;

scholarly journals Three-Dimensional Ring Current Decay Model

1995 ◽  
Vol 100 (A6) ◽  
pp. 9619 ◽  
Author(s):  
Mei-Ching Fok ◽  
Thomas E. Moore ◽  
Janet U. Kozyra ◽  
George C. Ho ◽  
Douglas C. Hamilton
Keyword(s):  
Ring Current ◽  
Three Dimensional ◽  
Current Decay ◽  
Decay Model

A Monte Carlo model of the ring current decay

1997 ◽  
Vol 20 (3) ◽  
pp. 335-338 ◽  
Author(s):  
S Noël ◽  
G.W Prölss
Keyword(s):  
Monte Carlo ◽  
Ring Current ◽  
Monte Carlo Model ◽  
Current Decay

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
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