Source regions of low-latitude Pc1 pulsations and their relationship to the plasmapause

The polarization method of source location has been used on data from two low latitude stations (L = 1.9) to determine the exit region of structured Pc1 emissions from the magnetosphere into the ionosphere. Propagation directions in the ionospheric F2 duct can be inferred from measurements of polarization parameters made at the low latitude recording station. Measurements on six events indicated an average source L value of 3.2, which represented the sources being on the average 1.0 ± 0.5 Re inside the corresponding statistical plasmapause position.