Derivation of Exospheric Temperature at High Latitudes from Incoherent- Scatter Radar Data
Abstract
This thesis investigates the feasibility of using statistical methods to derive representative exospheric temperatures in the high-latitude ionosphere despite Joule heating effects. The study was based on two main premises: that Joule heating is spatially and temporally localized in the radar's field of view and that a contaminated neutral temperature population representing Joule heating can be separated from the non-enhanced temperature population by statistical means. Exospheric temperatures were derived from Sondrestrom incoherent-scatter radar data using the ion energy balance equation. The effect of the 0(+) -0 section was tested by increasing it in the ion energy equation by factor of 1.7. Since exospheric temperatures increased only an average of 10 K, the original cross section was used in the calculations. Tests also showed the calculations to be fairly insensitive to variations in the s parameter and the neutral temperature at 120 km, used in the Bates neutral temperature profile, as long as the s value was .02 or greater. Input parameters were drawn from the MSIS86 model atmosphere, and the s values used were always greater than .02. Three tests were used to delimit the lower (non-Joule-heated) population in each cycle of radar observations: the Student t test, the normal distribution test, and the chi-squared test. A mean exospheric temperature was computed for each temperature population determined by the tests. (jhd)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1990
- Accession Number
- ADA227721
Entities
People
- Willow Cliffswallow
Organizations
- Air Force Institute of Technology