Observations of a gradual transition between Ps 6 activity with auroral torches and surgelike pulsations during strong geomagnetic disturbances

Journal Article · Mon Aug 01 04:00:00 EDT 1988 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA093iA08p08713· OSTI ID:6919786

Steen, A; Collis, P N; Evans, D; Kremser, G; Capelle, S; Rees, D; Tsurutani, B T

A long-lasting large-amplitude pulsation event was observed on January 10, 1983, 0200--0600 UT (0411--0745 MLT) in the ionosphere and in the magnetosphere. In the ionosphere the characteristics of the pulsations changed from being Ps 6/auroral torches toward substorms and back to Ps 6 over the 4-hour period. At the geostationary orbit (6.6 Re) the corresponding characteristics were a modulation of the high-energy (greater than or equal to20 keV) particle intensity and plasma dropouts. Following the work by Rostoker and Samson (1984), we propose an interpretation of the event in which the pulsations are caused by the Kelvin-Helmholtz instability, during an interval of strong magnetospheric convection. The gradual transition between Ps 6 pulsations and substorm structures is interpreted as being different results of the Kelvin-Helmholtz instability, caused by different states of the magnetospheric convection. The proposed explanation forms the basis for a discussion on a simplified scheme of the substorm sequence. copyright American Geophysical Union 1988

• Research Organization: Swedish Institute of Space Physics, Kiruna
• OSTI ID: 6919786
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 93:A8; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHARGED-PARTICLE PRECIPITATION
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
HELMHOLTZ INSTABILITY
HYDROMAGNETIC WAVES
INSTABILITY
IONOSPHERE
MAGNETIC BAYS
PLANETARY IONOSPHERES
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PULSATIONS
WAVE PROPAGATION