The STP/S3-4 Satellite Experiment: High Latitude Large Scale Density Irregularities.
Abstract
Large scale density irregularities in the nighttime auroral zone F-region are routinely detected by a pair of pulsed plasma probes on the s3-4 satellite. The absolute density variations can be as large as an order of magnitude and in the case of a quiet diffuse aurora, the irregularities appear to be consistent with the sheet-like structures that have been postulated to explain high latitude scintillation enhancements. In a more dynamic situation, which we believe to be a surging aurora, the density variations may be associated with a density gradient and/or current-driven plasma instability. We have made preliminary analyses of the density fluctuations and FFT power spectra for evidence of characteristic scale sizes and power law dependence. Scale sizes from 10-300 km are clearly evident in the irregularities; power law fits to the spectra have spectral indices in the range -1.5 to -1.7. For the diffuse aurora our results suggest support for a recent numerical study of the nonlinear evolution of the current convective instability. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 26, 1981
- Accession Number
- ADA100363
Entities
People
- D. N. Walker
- Edward P. Szuszczewicz
- J. C. Holmes
- Manish Singh
- P. Rodriguez
Organizations
- United States Naval Research Laboratory