Properties of the neutral energetic atoms emitted from Earth’s ring current region

2002 ◽  
Vol 9 (9) ◽  
pp. 3984-3994 ◽  
Author(s):  
C. Shen ◽  
Z. X. Liu
Keyword(s):  
Ring Current ◽  
Current Region

scholarly journals First current density measurements in the ring current region using simultaneous multi-spacecraft CLUSTER-FGM data

2005 ◽  
Vol 23 (5) ◽  
pp. 1849-1865 ◽  
Author(s):  
C. Vallat ◽  
I. Dandouras ◽  
M. Dunlop ◽  
A. Balogh ◽  
E. Lucek ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Current Density ◽  
Ring Current ◽  
Magnetic Activity ◽  
Activity Level ◽  
Local Current Density ◽  
Magnetospheric Configuration And Dynamics ◽  
Local Current ◽  
Current Region ◽  
First Time

Abstract. The inner magnetosphere's current mapping is one of the key elements for current loop closure inside the entire magnetosphere. A method for directly computing the current is the multi-spacecraft curlometer technique, which is based on the application of Maxwell-Ampère's law. This requires the use of four-point magnetic field high resolution measurements. The FGM experiment on board the four Cluster spacecraft allows, for the first time, an instantaneous calculation of the magnetic field gradients and thus a measurement of the local current density. This technique requires, however, a careful study concerning all the factors that can affect the accuracy of the J estimate, such as the tetrahedral geometry of the four spacecraft, or the size and orientation of the current structure sampled. The first part of this paper is thus providing a detailed analysis of the method accuracy, and points out the limitations of this technique in the region of interest. The second part is an analysis of the ring current region, which reveals, for the first time, the large latitudinal extent of the ring current, for all magnetic activity levels, as well as the latitudinal evolution of the perpendicular (and parallel) components of the current along the diffuse auroral zone. Our analysis also points out the sharp transition between two distinct plasma regions, with the existence of high diamagnetic currents at the interface, as well as the filamentation of the current inside the inner plasma sheet. A statistical study over multiple perigee passes of Cluster (at about 4 RE from the Earth) reveals the azimuthal extent of the partial ring current. It also reveals that, at these distances and all along the evening sector, there isn't necessarily a strong dependence of the local current density value on the magnetic activity level. This is a direct consequence of the ring current morphology evolution, as well as the relative positioning of the spacecraft with respect to the bulk of the ring current. It also proves the existence of a substantial ring current at these distances, all over the evening and the post-midnight sector. Keywords. Magnetospheric physics (Current systems; Energetic particles, trapped; Magnetospheric configuration and dynamics)

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.

scholarly journals A quantitative model of the magnetosphere with poloidal vector fields

1998 ◽  
Vol 16 (12) ◽  
pp. 1557-1566 ◽  
Author(s):  
J. C. Kosik
Keyword(s):  
Magnetic Field ◽  
Vector Fields ◽  
Ring Current ◽  
Computer Time ◽  
Quantitative Model ◽  
Magnetospheric Configuration And Dynamics ◽  
Current Region ◽  
Magnetospheric Configuration ◽  
Distant Field ◽  
Dependent Field

Abstract. A quantitative model of the magnetospheric magnetic field is developed using poloidal vector fields. This formalism is applied to the ring current region, the distant field and the return currents. The tail model is similar to the unwarped model of Tsyganenko. Several sets of coefficients are obtained for different Kp through a fit of the NSSDC data base. Experimental ΔB contours and theoretical distributed currents contours are correctly described and are Kp-dependent. Field line topology problems and poor ring current description observed in models of similar complexity are avoided. Computer time has been kept reasonable and makes this model particularly adapted to intensive-type calculations.Key words. Magnetospheric physics (magnetospheric · configuration and dynamics).  

Cluster Curlometry Limitations in the Ring Current Region

2021 ◽  
Author(s):  
Timothy B Keebler ◽  
Michael Liemohn ◽  
Natalia Ganushkina
Keyword(s):  
Ring Current ◽  
Current Region

scholarly journals Saturation of Alfven oscillations in the ring current region due to generation of lower hybrid waves

1992 ◽  
Vol 40 (4) ◽  
pp. 477-479 ◽  
Author(s):  
K.V. Gamayunov ◽  
E.N. Krivorutsky ◽  
A.A. Veryaev ◽  
G.V. Khazanov
Keyword(s):  
Ring Current ◽  
Lower Hybrid ◽  
Current Region ◽  
Hybrid Waves ◽  
Lower Hybrid Waves

scholarly journals Storm-time longitudinally propagating asymmetric modes at low latitudes

2012 ◽  
Vol 30 (1) ◽  
pp. 131-141 ◽  
Author(s):  
A. K. Singh ◽  
A. K. Sinha ◽  
R. Rajaram ◽  
B. M. Pathan
Keyword(s):  
Local Time ◽  
Ring Current ◽  
Detailed Examination ◽  
Global Scale ◽  
Low Latitude ◽  
Asymmetric Component ◽  
Low Latitudes ◽  
Magnetometer Data ◽  
Current Region ◽  
Rotation Of The Earth

Abstract. The westward flowing toroidal ring current at about 2–7 RE in the Earth's equatorial plane consists of symmetric and asymmetric parts. Zonal mean of H disturbances from longitudinally distributed low latitude stations represents the symmetric contribution, whereas departure from the zonal mean gives local time dependent asymmetric component at each of the stations. Through a standard analysis of closely spaced low latitude geomagnetic data we demonstrate 24 h periodicity in the asymmetric component of the storm-time ring current, which is related to the changing local time due to rotation of the Earth. Detailed examination of shorter period oscillations, when observed globally, often show westward propagating modes. Eastward propagating mode was also observed in one case. Based on satellite and radar observations covering a narrow longitude region, westward and eastward propagating modes had been reported in earlier studies. In this study, we report that similar propagating modes which are available on global scale, can be identified using ground-based magnetometer data. These globally propagating modes, observed from ground-based studies, find obvious practical application in diagnostics of the magnetosphere, especially the ring current region. Simultaneous use of satellite and ground-based data should establish the morphology of such modes.

scholarly journals THEMIS observations of penetration of the plasma sheet into the ring current region during a magnetic storm

2008 ◽  
Vol 35 (17) ◽  
Author(s):  
Chih-Ping Wang ◽  
Larry R. Lyons ◽  
Vassilis Angelopoulos ◽  
Davin Larson ◽  
J. P. McFadden ◽  
...  
Keyword(s):  
Magnetic Storm ◽  
Plasma Sheet ◽  
Ring Current ◽  
Current Region

Solar and ionospheric plasmas in the ring current region

2005 ◽  
pp. 179-194 ◽  
Author(s):  
T. E. Moore ◽  
M-C. Fok ◽  
S. P. Christon ◽  
S.-H. Chen ◽  
M. O. Chandler ◽  
...  
Keyword(s):  
Ring Current ◽  
Current Region

Quasielectrostatic instabilities excited by energetic oxygen ions in the ring current region

2005 ◽  
Vol 12 (1) ◽  
pp. 012903 ◽  
Author(s):  
S. V. Singh ◽  
A. P. Kakad ◽  
G. S. Lakhina
Keyword(s):  
Ring Current ◽  
Oxygen Ions ◽  
Current Region
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