Asymmetry in the electric and magnetic field polarization of geomagnetic pulsations

Simultaneous measurements of the electric and magnetic field of ULF waves a t ground and balloon heights have revealed polarizations of opposite handed ness. Magnetosonic wave propagation through a horizontally homogeneous high -latitude ionosphere experiences a polarization change (elliptization and r otation). It is shown that the polarization change continues further throug h the atmosphere and results in different polarization stales for the elect ric and magnetic fields. The opposite handedness of the Pc5 wave polarizati on recorded at the South Pole by measurements of the electric and magnetic field components [Bering, E.A., Benbrook, J.R., Byrne, G.J., Liao, B., Thea ll, J.R., Lanzerotti, L.J., Maclennan, C.G., 1995. Baloon measurements abov e the South Pole: study of ionospheric transmission of ULF waves. J. Geophy s. Res. 100(A5), 7807-7819.] might be explained as a result of an initial l eft-hand polarization of the ULF wave generated above the ionosphere and by an additional right-hand polarization effect in the ionosphere/atmosphere produced mostly on the wave magnetic field. (C) 1999 Elsevier Science Ltd. All rights reserved.