Electron temperature and concentration in the plasmasphere at an altitude of 3000km from Isis-1 Langmuir probe measurements

Abstract

Langmuir probe data from Isis-1 satellite are used to study the latitudinal profiles of electron temperature and concentration in the plasmasphere at an altitude of 3000 km. The electron temperature reveals minimum values in the equatorial latitudes and indicates appreciable diurnal variation in all seasons, with an average temperature of about 5000 K during daytime and about 2000 K during nighttime. The electron temperature starts increasing towards midlatitudes and then peaks near plasma trough region attaining an average temperature of more than 5500 K both during day and night. The electron concentration reveals maximum value in the equatorial latitudes. This equatorial maximum of electron concentration does not show any significant diurnal or seasonal change. There is a large latitudinal gradient in electron concentration near the plasma trough region where it decreases by more than a factor of 6 from its equatorial maximum value.