Equatorial Spread F: 'In Situ' Measurements of Electron Density Temperature and Density Fluctuation Power Spectra.
Abstract
The NRL pulsed plasma probe experiment was successfully flown on each of the two PLUMEX rockets during July 1979. The experiment provided direct measurements of absolute density N(e), temperature T(e) and density fluctuation power spectra with a maximum Nyquist frequency of 1 KHz (1 meter resolution at a 1 km/sec rocket velocity). In the first operation, a number of major depletions were distributed throughout the F-region, from its bottomside gradient centered near 260 km, through the F-peak, to a topside altitude of 500 km. The F-peak was at 375 km, with N(e)(Max) = 1/1,300,000 cc (+ or - 10%). The electron energy distribution was characterized by T(e) = 1350 (+ or - 250)K with no obvious signature of energy redistribution in and around the depletions. The most intense 'in situ' irregularities occurred on the bottomside ledge where gradient scale lengths were found to vary between 2 and 25 km. The power spectral density in this region of intense irregularities on the bottomside was dominated by a k(-2.5) power law over the intermediate wavelength domain k = 2pi/1 km to k = 2pi/2.5 m. This result supports the role of the collisional Rayleigh-Taylor instability in generating intermediate wavelength irregularities during the occurrence of equatorial spread-F.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 25, 1980
- Accession Number
- ADA089133
Entities
People
- Edward P. Szuszczewicz
- J. C. Holmes
Organizations
- United States Naval Research Laboratory