Studying the structure of ULF oscillations near the plasmapause, given heavy ions in magnetospheric plasma

This paper deals with the spatial structure of ULF (ultra-low-frequency) oscillations in the Pel frequency range near the plasmapause, given the admixture of heavy ions. The radial profile of the Alfven velocity has a minimum in this region, which localizes waves near the plasmapause and makes them propagate along the line of force. These waves appear on the equator and are localized in the resonator, limited by turning points, due to the presence of heavy ions in plasma. Eigenfrequencies of waves excited in the resonator are obtained using the WKB approximation with respect to the coordinates along the magnetic field.