Theoretical study of the high-latitude ionosphere's response to multicell convection patterns

Journal Article · Sat Aug 01 04:00:00 EDT 1987 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA092iA08p08733· OSTI ID:6267974

Sojka, J J; Schunk, R W

It is well known that the convection electric fields have an important effect on the ionosphere at high latitudes and that a quantitative understanding of their effect requires a knowledge of the plasma convection pattern. When the interplanetary magnetic field (IMF) is southward, plasma convection at F region altitudes displays a two-cell pattern with antisunward flow over the polar cap and return flow at lower latitudes. However, when the IMF is northward, multiple convection cells can exist, with both sunward flow and auroral precipitation (theta aurora) in the polar cap. The characteristic ionospheric signatures associated with multicell convection patterns were studied with the aid of a three-dimensional time-dependent ionospheric model. Two-, three-, and four-cell patterns were considered and the ionosphere's response was calculated for the same cross-tail potential and for solar maximum and winter conditions in the northern hemisphere. As expected, there are major distinguishing ionospheric features associated with the different convection patterns, particularly in the polar cap. For two-cell convection the antisunward flow the plasma from the dayside into the polar cap. For two-cell convection the antisunward flow of plasma from the dayside into the polar cap acts to maintain the densities in this region in winter. For four-cell convection, on the other hand, the two aditional convection cells in the polar cap are in darkness most of the time, and the resulting O/sup +/ decay acts to produce twin polar holes that are separated by a sun-aligned ridge of enhanced ionization due to theta aurora precipitation.

• Research Organization: Center for Atmospheric and Space Sciences, Utah State University, Logan
• OSTI ID: 6267974
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 92: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
AURORAE
CHARGED PARTICLES
CHARGED-PARTICLE PRECIPITATION
CONVECTION
EARTH ATMOSPHERE
ELECTRIC FIELDS
ELECTRON DENSITY
ELECTRON PRECIPITATION
ELEMENTS
ENERGY TRANSFER
F REGION
HEAT TRANSFER
INTERPLANETARY MAGNETIC FIELDS
IONOSPHERE
IONS
MAGNETIC FIELDS
MASS TRANSFER
MATHEMATICAL MODELS
NITROGEN
NONMETALS
OXYGEN IONS
PLANETARY IONOSPHERES
PLASMA DRIFT
POLAR REGIONS
SEASONAL VARIATIONS
VARIATIONS