Unidentified plasma irregularities in the equatorial electrojet

Describes observed characteristics of an as-yet-unidentified family of plasma irregularities found in the E-region of the equatorial ionosphere. The irregularities are casually related to the equatorial electrojet-an electron current flowing parallel to the magnetic dip equator (the dip equator is defined as the locus of points where the Earth's magnetic field is horizontal). This current is concentrated in height between about 105 and 115 km above the Earth's surface, and in latitude to within about 300 km either side of the dip equator. It is the result of a polarization field set up by a vertical Hall current which is driven by the world-wide system of 'dynamo' electric fields (cf. Matsushita, 1962).