Average low-latitude meridional electric fields from DE 2 during solar maximum

Technical Report · Sun May 01 04:00:00 EDT 1988

OSTI ID:6483493

Maynard, N; Aggson, T; Herrero, F; Liebrecht, M

Electric-field data from the double-probe vector electric-field instrument (VEFI) on the DE 2 spacecraft were analyzed to determine the average meridional electric-field (zonal ion flow) patterns in the region between + or - 30 deg magnetic latitude during solar maximum conditions. Over 300 passes were used to compile the data set. Data were projected to a constant 300-km altitude and to the equatorial plane assuming that the electric field along the magnetic field was zero. The average data set displayed a rapid increase of the downward meridional electric field with local time near 1800 MLT with the higher latitudes seeing the change first. A secondary nighttime maximum of this electric-field component was observed past midnight with the crossover to upward electric fields (westward ion flow) occurring between 0400 and 0500 MLT. A sharp return to near zero was observed between 1200 and 1300. Typical average amplitudes range between 3 and 6 mV/m. No consistent variations with magnetic activity were observed. Although the daily variation in the zonal ion flow is dominated by the diurnal term, a net superrotation is evident in the harmonic analysis. The superrotation is strongest near the equator and decreases with latitude, because of the disturbance dynamo. The higher order harmonics up through the quatrediurnal term are also of significant magnitude in the analysis of the shape of the daily variation. Close similarity is seen to the zonal neutral winds indicating that they form the principal driving force. The magnitudes of the electric field derived ion drift are somewhat higher than the average F-region neutral-wind values.

• Research Organization: Air Force Geophysics Lab., Hanscom AFB, MA (USA)
• OSTI ID: 6483493
• Report Number(s): AD-A-200338/2/XAB; AFGL-TR-88-0289
• Country of Publication: United States
• Language: English

Related Subjects

640104 -- Astrophysics & Cosmology-- Solar Phenomena
640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHARGED PARTICLES
EARTH ATMOSPHERE
ELECTRIC FIELDS
F REGION
HARMONICS
IONOSPHERE
IONOSPHERIC EFFECTS
IONS
MAGNETIC FIELDS
OSCILLATIONS
PLANETARY IONOSPHERES
SOLAR ACTIVITY
TROPICAL REGIONS
VISIBILITY
WIND