HELIUM-IONS IN THE MID-LATITUDE PLASMASPHERE

An initial study of the behaviour of He+ ions in the mid-latitude plasmasphere is carried out by solving the time-dependent equations of continuity and momentum. Starting with a low He+ tube content, results are obtained for a period of 8 days. In the topside ionosphere there is an upflow of He+ during the day and downflow at night, for the sunspot maximum conditions considered. The downflow at night differs from the behaviour of H+ for these atmospheric conditions. However, little of the He+ produced in the daytime is lost by recombination at night; it is suggested that the supply of He+ to the mid-latitude plasmasphere is, in effect, an escape process for neutral helium. © 1979.