Ionospheric convection signatures and magnetic field topology

Journal Article · Sun Nov 01 04:00:00 EST 1987 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA092iA11p12352· OSTI ID:5514046

Coley, W R; Heelis, R A; Hanson, W B; Reiff, P H; Sharber, J R; Winningham, J D

We present here a statistical study of signatures of the high-latitude ionospheric convection pattern and the simultaneously observed energetic electron precipitation. We most often find convection cells in which the sunward flowing region contains auroral particle precipitation but the antisunward flowing region does not. However, our observations also show the frequent occurrence of convection cells in which neither the antisunward nor the sunward flowing plasma region contains auroral particle precipitation. These findings may appear within the dawnside or duskside convection pattern and strongly suggest that such convection cells may be associated with open magnetic field lines that thread the magnetotail lobes. Examination of the interplanetary magnetic field (IMF) data shows that this ''lobe cell'' convection signature is most likely to be accompanied by the signature of dayside merging when the IMF has a significant y component but is directed southward. A lobe convection cell has a location and sense of circulation that are dependent on the sign of B/sub y/. For the northern hemisphere, clockwise circulation displaced to the duskside appears roughly 35% of the time when B/sub y/ is positive, and anticlockwise circulation displaced to the dawnside appears when B/sub y/ is negative. The same circulation sense and location exist in the southern hemisphere for the opposite polarity of B/sub y/. At times of northward IMF, the circulation within the polar cap can be at least partially on closed field lines and cannot be easily reconciled with merely a distortion of the standard ''two-cell'' convection pattern. The significance of these results to several models of the solar wind/magnetosphere interaction is discussed. copyright American Geophysical Union 1987

• Research Organization: Center for Space Sciences, University of Texas at Dallas, Richardson, Texas
• OSTI ID: 5514046
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 92:A11; 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
AURORAE
CHARGED-PARTICLE PRECIPITATION
CONVECTION
CONVECTIVE INSTABILITIES
DAILY VARIATIONS
DATA
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRON PRECIPITATION
ENERGY TRANSFER
HEAT TRANSFER
INFORMATION
INSTABILITY
IONIC COMPOSITION
IONOSPHERE
MAGNETIC FIELD CONFIGURATIONS
MAGNETOTAIL
MASS TRANSFER
NUMERICAL DATA
PLANETARY IONOSPHERES
PLASMA DRIFT
PLASMA INSTABILITY
POLAR REGIONS
STATISTICAL DATA
TIME DEPENDENCE
VARIATIONS