On the origin of blanketing and diffused sporadic E layers at equatorial and low latitudes

Abstract

Electron density data obtained over the dip equator using rocket-borne high resolution Langmuir probes is examined during the presence of blanketing (Es-b) as well as diffused type (Es-q) sporadic E layers in the ionosphere. Plasma irregularities are found to exist in both the cases which could be ascribed to the crossfield instability mechanism. It is found that the irregularities are located in the bottomside gradient portion in the E region when Es-q is generated and on the topside gradient portion of a sublayer produced during Es-b. This behavior is interpreted in terms of the orientation and shape of the plasma irregularities which in both cases are found to have a saw-tooth structure.