PLUMEX II. A Second Set of Coincident Radar and Rocket Observations of Equatorial Spread-F.
Abstract
PLUMEX II was the second in a two-rocket operation that successfully executed space- and time-coincident measurements of equatorial spread-F. The first launch operation (PLUMEX I) was conducted during the late phase in the development and decay of spread-F; major radar plume features were relatively stable with respect to vertical drifts, and the most intense regions of radar backscatter were beginning to decay. The PLUMEX II conditions were substantially different, with the rocket having been launched into the mid-phase of well developed spread-F, i.e., a ground-based ionosonde showed full range spread while Altair radar maps of meter-size irregularities displayed backscatter plumes that penetrated to the topside F-layer and continued rising with time. Current analysis of PLUMEX II results show that F-region irregularities were observed only on the bottomside gradient with F sub 2 h(max) at 510 km and N sub e(max) approx. = 600,000/cu cm. Smaller scale irregularities (i.e., small scale structure imbedded in larger scale features) appear less intense than corresponding observations in PLUMEX I. If substantiated by more quantitative analyses, this result could support current interpretations of east-west plume asymmetry which suggests that the western wall of a plume (the PLUMEX I case) is more unstable than its eastern counterpart (the PLUMEX II case). With regard to ion composition, NO(+) was the dominant positive-charge component at altitudes below the F-region ledge. Across the ledge and throughout the F-layer up to an apogee of 580 km 0(+) dominated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 30, 1980
- Accession Number
- ADA096279
Entities
People
- Edward P. Szuszczewicz
- J. C. Holmes
- R. Narcisi
- R. T. Tsunoda
Organizations
- United States Naval Research Laboratory