Magnetic storm of September 4, 1984: A synthesis of ring current spectra and energy densities measured with AMPTE/CCE

1985 ◽  
Vol 12 (5) ◽  
pp. 329-332 ◽  
Author(s):  
S. M. Krimigis ◽  
G. Gloeckler ◽  
R. W. McEntire ◽  
T. A. Potemra ◽  
F. L. Scarf ◽  
...  
Keyword(s):  
Magnetic Storm ◽  
Ring Current

scholarly journals <i>Swarm</i> field-aligned currents during a severe magnetic storm of September 2017

2019 ◽  
Author(s):  
Renata Lukianova
Keyword(s):  
Magnetic Storm ◽  
Ring Current ◽  
Current System ◽  
Small Scale ◽  
Substantial Fraction ◽  
H Index ◽  
Swarm Satellites ◽  
Scale Field ◽  
Extreme Behavior ◽  
A Current

Abstract. Swarm satellites observations are used to characterize the extreme behavior of large- and small-scale field-aligned currents (FACs) during the severe magnetic storm of September 2017. Evolution of the current intensities and the equatorward displacement of FACs are analyzed while the satellites cross the pre-midnight, pre-noon, dusk and dawn sectors in both hemispheres. The equatorward boundaries of FACs mainly follow the dynamics of ring current (as monitored in terms of the SYM-H index). The minimum latitude of the FAC boundaries is limited to 50° MLat, below which saturation occurs. The FAC densities are very variable and may increase dramatically, especially in the nightside ionosphere during the storm-time substorms. At the peak of substorm, the average FAC densities reach 3 μA/m2, while the quite level is below 0.1 μA/m2. The dawn–dusk asymmetry is manifested in the enhanced dusk-side R2 FACs in both hemispheres. Filamentary high-density structures are always observed confirming that a substantial fraction of R1/R2 FACs is composed of many small-scale currents. In the pre-noon sector, the bipolar structures (7.5 km width FACs of opposite polarities adjacent to each other) dominate, while in the post-midnight sector the upward and downward FACs tend to form more latitudinally extended structures of a certain polarity. The most intense small-scale FACs (up to ~80 μA/m2) is observed just in the post-midnight sector. Simultaneous magnetic and plasma perturbations indicate that this structure is likely a current system of a mesoscale auroral arc.

Multi-Step Dst Development and Ring Current Composition Changes During the 4-6 Jun 1991 Magnetic Storm

2001 ◽  
Author(s):  
J. U. Kozyra ◽  
M. W. Liemohn ◽  
C. R. Clauer ◽  
J. Ridley ◽  
M. F. Thomsen
Keyword(s):  
Magnetic Storm ◽  
Ring Current ◽  
Composition Changes

Ring current asymmetry during a magnetic storm

2008 ◽  
Vol 48 (6) ◽  
pp. 747-758 ◽  
Author(s):  
V. V. Kalegaev ◽  
K. Yu. Bakhmina ◽  
I. I. Alexeev ◽  
E. S. Belenkaya ◽  
Ya. I. Feldstein ◽  
...  
Keyword(s):  
Magnetic Storm ◽  
Ring Current

Some initial ISEE-1 results on the ring current composition and dynamics during the magnetic storm of December 11, 1977

1979 ◽  
Vol 6 (6) ◽  
pp. 483-486 ◽  
Author(s):  
W. Lennartsson ◽  
E. G. Shelley ◽  
R. D. Sharp ◽  
R. G. Johnson ◽  
H. Balsiger
Keyword(s):  
Magnetic Storm ◽  
Ring Current

scholarly journals 33. The present state of the corpuscular theory of magnetic storms

1958 ◽  
Vol 6 ◽  
pp. 295-311
Author(s):  
V. C. A. Ferraro
Keyword(s):  
Magnetic Field ◽  
Magnetic Storm ◽  
Ring Current ◽  
Plane Surface ◽  
Magnetic Storms ◽  
Main Phase ◽  
Polar Regions ◽  
Stream Surface ◽  
The Earth ◽  
The Magnetic Field

The evidence in favour of a corpuscular theory of magnetic storms is briefly reviewed and reasons given for believing that the stream must be neutral but ionized and carry no appreciable current. It is shown that under suitable conditions the stream is able to pass freely through a solar magnetic field; the stream may also be able to carry away with it a part of this field. However, because of geometrical broadening of the stream during its passage from the sun to the earth, the magnetic field imprisoned in the gas may be wellnigh unobservable near the earth.The nature, composition and dimensions of the stream near the earth are discussed and it is concluded that on arrival the stream will present very nearly a plane surface to the earth if undistorted by the magnetic field.Because of its large dimensions, the stream will behave as if it were perfectly conducting. During its advance in the earth's magnetic field the currents induced in the stream will therefore be practically confined to the surface. The action of the magnetic field on this current is to retard the surface of the stream which being highly distortible will become hollowed out. Since the stream surface is impervious to the interpenetration of the magnetic tubes of force, these will be compressed in the hollow space. The intensity of the magnetic field is thereby increased and this increase is identified with the beginning of the first phase of a magnetic storm. This increase will be sudden, as observed, owing to the rapid approach of the stream to the earth.The distortion of the stream surface is discussed and it is pointed out that two horns will develop on the surface, one north and the other south of the geomagnetic equator. Matter pouring through these two horns will find its way to the polar regions.The main phase of a magnetic storm seems most simply explained as due to a westward ring-current flowing round the earth in its equatorial plane. Under suitable conditions such a ring-current would be stable if once set up. The mode of formation of the ring is, however, largely conjectural. The possibility that the main phase may be of atmospheric origin is also briefly considered. It is shown that matter passing through the two horns to the polar regions could supply the energy necessary for the setting up of the field during the main phase. The magnetic evidence in favour of such a hypothesis, however, seems wanting.

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