|
Titel |
HF radar observations of equatorial spread-F over West Africa |
VerfasserIn |
J.-F. Cécile, P. Vila, E. Blanc |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
0992-7689
|
Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 14, no. 4 ; Nr. 14, no. 4, S.411-418 |
Datensatznummer |
250012257
|
Publikation (Nr.) |
copernicus.org/angeo-14-411-1996.pdf |
|
|
|
Zusammenfassung |
New experimental data depicting equatorial
spread-F were taken during an HF radar sounding campaign in Korhogo (Ivory
Coast, 9°24N, 5°37W, dip 4°S). Range-time-intensity maps of the radar echoes
have been analyzed to identify the signatures of density depletions and
bottomside spread-F. Density depletions are well known features of equatorial
spread-F, and are believed to emerge after the development of a Rayleigh-Taylor
instability on the bottomside F-layer. A simple model is developed and used to
simulate the flow of density depletions over the radar field of view. The
simulation permits an interpretation of the data that yields the zonal flow
velocity as a function of local time. Comparisons with previous measurements are
undertaken to assess the consistency of the computational results, and
qualitative arguments are presented to identify bottomside spread-F. Using the
computational results as reference, a morphological study of ionograms showing
spread-F is undertaken which reveals the specific signature of bottomside
spread-F on ionograms recorded just after sunset. |
|
|
Teil von |
|
|
|
|
|
|