Determination of Propagation Path Latitude and Plasma Density from Pc 1 Emissions

Abstract

The normalized dispersion curve method taking into account the presence of helium ions is used to determine plasma densities in the magnetosphere from the dispersion characteristics of Pc 1 emissions. The determination of equatorial distances to the propagation paths of Pc 1 emissions indicates that the inferred source location of Pc 1 signals lies on the plasmapause. The phase trapping length along the geomagnetic field line from the equatorial plane is estimated as functions of wave amplitudes and proton pitch angles. It is found that an increase of helium ion concentration tends to produce a detrapping effect on the high frequency branch of ion cyclotron waves in the dispersion diagram.