Ionospheric frequency spread and its relationship with range spread in mid‐latitude regions
- 1 June 1991
- journal article
- Published by American Geophysical Union (AGU) in Journal of Geophysical Research
- Vol. 96 (A6) , 9745-9753
- https://doi.org/10.1029/91ja00389
Abstract
The distinction between range spread and frequency spread as seen on mid‐latitude ionograms is discussed. A classification of these two types of spread F is proposed in terms of different arrangements of the duplicate traces which provide the basic trace structures of mid‐latitude spread F ionograms. Experimental results are presented to support the idea that frequency spread results from multiple ray paths (associated with a shallow ripple structure in the isoionic contours) close to the direction of the zenith position, so that each ray path has a range approximately equal to that of its neighbor. Furthermore, a horizontal gradient of maximum electron density is an additional requirement to create frequency spread. Atmospheric conditions (involving ionospheric F2 region heights and upper atmosphere neutral particle densities) which seem to favor the generation of frequency spread are discussed.Keywords
This publication has 29 references indexed in Scilit:
- Latitude dependence of the time delay in spread-F occurrence following geomagnetic activityJournal of Atmospheric and Terrestrial Physics, 1979
- A relationship between polar magnetic substorms, ionospheric height rises and the occurrence of spread-FJournal of Atmospheric and Terrestrial Physics, 1978
- The aspect sensitivity of spread-F irregularitiesJournal of Atmospheric and Terrestrial Physics, 1971
- Aspect sensitivity of F-layer HF backscatter echoesJournal of Geophysical Research, 1970
- The Nature of Spread?F Irregularities in AntarcticaAustralian Journal of Physics, 1968
- Spread-F in the Ionosphere and the Neutral Particle Density of the Upper AtmosphereNature, 1964
- Further studies of “Spread-F” at Brisbane-II interpretationPlanetary and Space Science, 1960
- Further studies of “Spread-F” at Brisbane-I experimentalPlanetary and Space Science, 1960
- The height of F-layer irregularities in the Arctic ionosphereJournal of Geophysical Research, 1959
- Scattering of radio waves by the F‐region of the ionosphereTerrestrial Magnetism and Atmospheric Electricity, 1938