Thumbnail
Access Restriction
Open

Author Yahnin, A. ♦ Malkov, M. V. ♦ Sergeev, V. A. ♦ Pellinene, R. J. ♦ Aulamo, O. ♦ Vennerstroem, S. ♦ Friis-Christensen, E. ♦ Lassen, K. ♦ Danielsen, C. ♦ Craven, J. D.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PHYSICS ♦ POLAR CUSP ♦ CHARGED-PARTICLE PRECIPITATION ♦ AURORAE ♦ MAGNETIC FLUX ♦ STABILITY ♦ EARTH MAGNETOSPHERE ♦ CONVECTION ♦ INTERPLANETARY MAGNETIC FIELDS
Abstract The large-scale patterns of ionospheric convection and particle precipitation are described during two intervals of steady magnetospheric convection (SMC) on November 24, 1981. The unique data set used in the analysis includes recordings from the worldwide network of magnetometers and all-sky cameras, global auroral images from the DE 1 spacecraft, and particle precipitation data from low-altitude NOAA 6 and NOAA 7 spacecraft. The data show that intense magnetospheric convection continued during more than 10 hours under the steady southward interplanetary magnetic field without any distinct substorm signatures. All data sets available confirmed the stable character of the large-scale magnetospheric configuration during this period. In particular, the magnetic flux threading the polar cap was stable (within 10%) during 3.5 hours of continued DE 1 observations. The dayside cusp was located at an unusually low latitude (70{degrees} CGL). The nightside auroral pattern consisted of two distinct regions. The diffuse aurora in the equatorward half of the expanded (10{degrees} wide) auroral oval was well-separated from the bright, active auroral forms found in the vicinity of the poleward boundary of the oval. The twin-vortex convection pattern had no signature of the Harang discontinuity; its nightside {open_quotes}convection throat{close_quotes} was spatially coincident with the poleward active auroras. This region of the auroral oval was identified as the primary site of the short-lived transient activations during the SMC intervals. The energetic particle observations show that the auroral oval was identified as the primary site of the short-lived transient activations during the SMC intervals. The energetic particle observations show that the auroral precipitation up to its high-latitude limit is on closed field lines and that particle acceleration up to > 30-keV energy starts close to this limit. 34 refs., 11 figs., 1 tab.
ISSN 01480227
Educational Use Research
Learning Resource Type Article
Publisher Date 1994-03-01
Publisher Place United States
Journal Journal of Geophysical Research
Volume Number 99
Issue Number A3


Open content in new tab

   Open content in new tab