The Structure of Sporadic E From a Radio Experiment


  • J. D. Whitehead


An ionosonde has been used to measure the ordinary and extraordinary critical and blanketing frequencies separately. While the results support the idea that transparent sporadic-E reflections occur from small volumes within the E region, it is likely that the plasma density even in these volumes is often less than that required to cause total reflection. The structure of sporadic E is probably as follows: The peak plasma frequency varies by roughly equal amounts above and below a mean value often by a megahertz or so, within a few kilometers. Some intense blobs cause total reflection; other small volumes of increased plasma frequency strongly scatter radio waves of somewhat greater frequency.