Satellite Measurements of Auroral Coupling Processes,
Abstract
The high spatial-temporal resolution of instrumentation on the polar orbiting S3-2 satellite has allowed a wide variety of measurements of the electrodynamic characteristics of both large- and small-scale structures at high latitudes. Analyses of large scale features observed by S3-2 have shown that: (i) The IMF B sub y dependence of polar cap convection, first observed in June 1969 by OGO-6 persists in other seasons. During periods of northward IMF B sub z extensive regions of sunward convection may be found in the sunlit polar cap. (ii) In the dawn and dusk MLT sectors > 90% of the Region 1 currents lie equatorward of the convection reversal line. Potentials across the ionospheric projection of the low-latitude boundary layer are typically a few kV. (iii) The location of 'extra' field-aligned currents, near the dayside cusp and poleward of the Region 1 current sheet is dependent on the IMF B sub y component. (iv) Simultaneous observations by TRIAD and S3-3 show that sheets of field-aligned current extend uniformly for several hours in MLT, but may have an altitude dependence in the 1000-8000 km range. (v) During magnetic storms ionospheric irregularities generated by scintillations occur in regions of poleward density gradient and downward field aligned current near the equatorward boundary of diffuse auroral precipitation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1982
- Accession Number
- ADA139277
Entities
People
- R. C. Sagalyn
Organizations
- Air Force Research Laboratory