Ion composition during the formation of a midlatitude E sub S layer

The positive ion composition within a midlatitude sporadic E layer has been measured with the aid of a rocket-borne ion mass spectrometer launched from El Arenosillo, Spain on July 3, 1972 at 0743 LMT. Ionograms taken before and during the rocket flight showed a developing sporadic E layer near 114 km. Rocket data showed peaks in electron density and metallic ions at this same height. Both the maximum and total content of the metals are observed to be greater on the downleg than the upleg measurement.