Magnetospheric substorms and the sources of inner magnetosphere particle acceleration

2005 ◽  
pp. 105-111 ◽  
Author(s):  
E.E. Antonova
Keyword(s):  
Particle Acceleration ◽  
Magnetospheric Substorms ◽  
Inner Magnetosphere

scholarly journals Evidence for Particle Acceleration During Magnetospheric Substorms

1994 ◽  
Vol 142 ◽  
pp. 531-539
Author(s):  
Ramon E. Lopez ◽  
Daniel N. Baker
Keyword(s):  
Solar Wind ◽  
Particle Acceleration ◽  
Energy Release ◽  
Acceleration Of Particles ◽  
Magnetospheric Substorms ◽  
Geomagnetic Tail ◽  
Dissipation Of Energy ◽  
In Situ Observations ◽  
Current Systems

AbstractMagnetospheric substorms represent the episodic dissipation of energy stored in the geomagnetic tail that was previously extracted from the solar wind. This energy release produces activity throughout the entire magnetosphere-ionosphere system, and it results in a wide variety of phenomena such as auroral intensifications and the generation of new current systems. All of these phenomena involve the acceleration of particles, sometimes up to several MeV. In this paper we present a brief overview of substorm phenomenology. We then review some of the evidence for particle acceleration in Earth’s magnetosphere during substorms. Such in situ observations in this most accessible of all cosmic plasma domains may hold important clues to understanding acceleration processes in more distant astrophysical systems.Subject headings: acceleration of particles — Earth — solar wind

scholarly journals Interhemispheric asymmetries in the occurrence of magnetically conjugate sub-auroral polarisation streams

2005 ◽  
Vol 23 (4) ◽  
pp. 1371-1390 ◽  
Author(s):  
M. L. Parkinson ◽  
M. Pinnock ◽  
J. A. Wild ◽  
M. Lester ◽  
T. K. Yeoman ◽  
...  
Keyword(s):  
Electric Field ◽  
Auroral Oval ◽  
Particle Interactions ◽  
Magnetospheric Substorms ◽  
Polarisation Field ◽  
Energetic Ions ◽  
Inner Magnetosphere ◽  
Flux Tubes ◽  
Ion Drift ◽  
Magnetic Flux Tubes

Abstract. Earthward injections of energetic ions and electrons mark the onset of magnetospheric substorms. In the inner magnetosphere (L4), the energetic ions drift westward and the electrons eastward, thereby enhancing the equatorial ring current. Wave-particle interactions can accelerate these particles to radiation belt energies. The ions are injected slightly closer to Earth in the pre-midnight sector, leading to the formation of a radial polarisation field in the inner magnetosphere. This maps to a poleward electric field just equatorward of the auroral oval in the ionosphere. The poleward electric field is subsequently amplified by ionospheric feedback, thereby producing auroral westward flow channels (AWFCs). In terms of electric field strength, AWFCs are the strongest manifestation of substorms in the ionosphere. Because geomagnetic flux tubes are essentially equi-potentials, similar AWFC signatures should be observed simultaneously in the Northern and Southern Hemispheres. Here we present magnetically conjugate SuperDARN radar observations of AWFC activity observed in the pre-midnight sector during two substorm intervals including multiple onsets during the evening of 30 November 2002. The Northern Hemisphere observations were made with the Japanese radar located at King Salmon, Alaska (57, and the Southern Hemisphere observations with the Tasman International Geospace Environment Radar (TIGER) located at Bruny Island, Tasmania (55. LANL geosynchronous satellite observations of energetic ion and electron fluxes monitored the effects of substorms in the inner magnetosphere (L6). The radar-observed AWFC activity was coincident with activity observed at geosynchronous orbit, as well as westward current surges in the ionosphere observed using ground-based magnetometers. The location of AWFCs with respect to the auroral oval was inferred from FUV auroral images recorded on board the IMAGE spacecraft. DMSP SSIES ion drift measurements confirmed the presence of AWFCs equatorward of the auroral oval. Systematic asymmetries in the interhemispheric signatures of the AWFCs probably arose because the magnetic flux tubes were distorted at L shells passing close to the substorm dipolarisation region. Transient asymmetries were attributed to the development of nearby field-aligned potential drops and currents.

Collective Methods of Particle Acceleration in a Plasma and in Heavy-Current Electron Beams

1972 ◽  
Vol 107 (6) ◽  
pp. 326
Author(s):  
A.A. Kolomenskii ◽  
M.S. Rabinovich ◽  
Ya.B. Fainberg
Keyword(s):  
Particle Acceleration ◽  
Electron Beams ◽  
Current Electron
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