Auroral zone electric fields from DE 1 and 2 at magnetic conjunctions. Progress report

Technical Report · Thu Aug 01 04:00:00 EDT 1985

OSTI ID:6077433

Weimer, D R; Goertz, C K; Gurnet, D A; Maynard, N C; Burch, J L

Nearly simultaneous measurements of auroral zone electric fields are obtained by the Dynamics Explorer spacecraft at altitudes below 900 km and above 4500 km during magnetic conjunctions. The measured electric fields are usually nearly perpendicular to the magnetic field lines. The north-south meridional electric fields are projected to a common altitude by a mapping function which accounts for the convergence of the magnetic field lines. When plotted as a function of invariant latitude, graphs of the projected electric fields measured by DE1 and DE2 show that the large-scale electric field is the same at both altitudes, as expected. Superimposed on the large-scale fields, however, are small-scale features with wavelengths of less than 100 km which are larger in magnitude at the higher altitude. Fourier transforms of the electric fields show that the magnitudes depend on wavelength. Outside of the auroral zone the electric field spectrums are nearly identical. But within the auroral zone the high- and low-altitude electric fields have a ratio which increases with the reciprocal of the wavelength. The small-scale electric field variations are associated with field-aligned currents.

• Research Organization: Iowa Univ., Iowa City (USA). Dept. of Physics and Astronomy
• OSTI ID: 6077433
• Report Number(s): AD-A-159515/6/XAB
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALIGNMENT
ALTITUDE
AURORAE
AURORAL ZONES
CONVERGENCE
DISTRIBUTION
EARTH ATMOSPHERE
ELECTRIC FIELDS
EXPLORER SATELLITES
FOURIER TRANSFORMATION
INTEGRAL TRANSFORMATIONS
IONOSPHERE
MAGNETIC FIELDS
PLANETARY IONOSPHERES
SATELLITES
SPATIAL DISTRIBUTION
TRANSFORMATIONS