Ionospheric electrostatic fields and the equatorial electrojet

Abstract

The electrostatic characteristics associated with the equatorial electro jet are investigated with the aid of a number of theoretical and experimental considerations. With regard to the peak electro jet current, an eastward component of electric force of magnitude 4×10−4 volt/meter drives a current of density 10−5 amp/meter2. In the region of maximum current the ionosphere is electrically neutral, but the electric field is created by an electrostatic charge distribution with an excess of electrons in the region east of the point with peak current and an excess of positive charges in the region to the west. The maximum of the difference in the number density of the negative and positive charges is 5×10−2 charge/ meter3 for the volume density, and 9×104 charge/meter2 for the surface density on the lower boundary of the E layer. These number differences, which represent extremely small departures from electrical neutrality in the ionosphere, indicate the prime importance of a surface charge distribution in producing the ionospheric electrostatic field. The vertical component of the electrostatic force has a maximum value of 4×10−4 volt/meter but vanishes at the point containing the peak electro jet current.

A plasma instability resulting in field-aligned irregularities in the ionosphere

“…This polarization field enhances the horizontal current flow considerably. This intense current is generally called the equatorial electrojet, and it has been studied in considerable detail [Cahill, 1959;Onwumechilli, 1959;Zmuda, 1960;Ogbuehi and Onwumcchilli, 1963; and additional references listed therein], primaril y by measuring changes in the magnetic field on the ground, but also by rocket measurements.…”

“…Crude estimates [Zmuda, 1960;Matsushita, 1962] yield midday values of the order of 500 m/sec, subject to considerable day to day variation.…”

Energetic Particles in the Earth's Magnetic Field

“…They find these fluxes to be ", 103 cm -2 sec-I. This loss is a permanent feature of the radiation zone and may be responsible for certain features of the ionization in the D and E layers of the Earth's ionosphere at these latitudes (69,70).…”