Abstract:
The characteristics of spread-F at a temperate latitude station vis-à-vis those at an equatorial station in the same longitude zone are described. Temperate latitude spread signature on the ionogram is shown to be due to a number of off-vertical reflections superimposed over the normal vertical p’-f trace. At temperate latitude, the background f region ionization seems to increase during spread-F conditions. Onset time of spread-F seems to increase with distance from the equator, being about 1930 hrs at the equator, about 2200 hrs at the anomaly crest region, and about 0000 hrs at temperate latitudes.
