Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Observation of the plasma sheet during a contracted oval substorm in a prolonged quiet period

Journal Article · · J. Geophys. Res.; (United States)
This report presents an interesting observation of a substorm which occurred on a contracted oval, with simultaneous particle measurements by Imp 6 (rapprox.11 R/subE/) and ATS 5 (rapprox.6.6 R/subE/) satellites. At the substorm onset, immediate and substantial energization of both protons and electrons in the plasma sheet was observed by the Imp 6 satellite in the midnight sector. This change was accompanied by a strong earthward plasma flow at approx.500 km/s for approx.12 min. However, no significant mid-latitude positive bays were detected, and no substorm injection of plasma sheet particles was observed by the ATS 5 satellite, located then at approx.0130 MLT. This observation indicates that substorms occurring on a contracted oval are accompanied by two of the characteristic substorm changes in the plasma sheet, namely, the energization of the plasma sheet particles and the occurrence of strong plasma flows, but the substorm injection does not necessarily reach the synchronous distance in the midnight sector. Further, it suggests that contracted oval substorms and intense substorms represent the same physical phenomenon, differing only in magnitude. It is also shown that after a prolonged quiet period the average energies of protons and electrons in the near-earth plasma sheet (at approx.11 R/subE/) are as low as 2 keV and 100 eV, respectively. (AIP)
Research Organization:
Geophysical Institute, University of Alaska, Fairbanks, Alaska 99701
OSTI ID:
7268606
Journal Information:
J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 81:7; ISSN JGREA
Country of Publication:
United States
Language:
English

Similar Records

Proton flow measurements in the magnetotail plasma sheet made with Imp 6
Journal Article · Wed Dec 31 23:00:00 EST 1975 · J. Geophys. Res., v. 81, no. 1, pp. 227-234 · OSTI ID:4006210

Auroral displays near the foot of the field line of the ATS-5 satellite
Journal Article · Mon Dec 31 23:00:00 EST 1973 · Planet. Space Sci., v. 22, no. 1, pp. 25-40 · OSTI ID:4337204

Complete plasma dropouts at Vela satellites during thinning of the plasma sheet
Journal Article · Sun Nov 30 23:00:00 EST 1975 · J. Geophys. Res., v. 80, no. 34, pp. 4649-4659 · OSTI ID:4049153