Summary and conclusions from the estes park sporadic E seminar 1. Radio measurements

In a summary of the “radio” measurements of sporadic E we cannot extricate ourselves completely from consideration of the other measurements considered in this conference. For some purposes, the radio propagation characteristics provide us with a means of diagnosing properties of the E region; for other purposes, experimental results obtained in alternative ways permit us a means of interpreting the radio propagation. In this seminar it has been possible to bring more clearly into focus the physical relationship between the various radio propagation phenomena as observed from the ground and the electron density variations which cause these phenomena. For completeness, the field of “radio” measurements of Es should also include those rocket measurements which depend upon the integrated radio path from ground to rocket. These rocket measurements are distinct from the ground-based radio observations in that interpretation of the rocket observations yields a relatively unambiguous measure of atmospheric properties in a restricted volume centered on the rocket trajectory. The propagation phenomena which first provided us with the name “sporadic E” result from an integration of effects distributed over volumes some tens of km in extent.