Rocket Observations of Sporadic E and Related Features of the E Region

Observations of structural features of the electron density profile of the E region are presented. These were obtained using a rocket‐borne probe having a resolution of about 10 m in height and about 1 percent in electron density. Daytime profiles show thin‐layer E s having sharply defined upper and lower boundaries and a thickness of a few km. At night, the profiles at midlatitudes are characterized hy the generally irregular nature below 120 km. The marked tendency to horizontal stratification is noted.