Discrete magnetosonic waves as an evidence of nonlinear wave-particle interaction

Two events, showing strong emissions near the lower hybrid frequency, are studied in detail in this paper. By analyzing the polarization degree, wave normal angle, and ellipticity, we conclude that the emissions are magnetosonic (MS) waves. These MS waves have opposite poynting fluxes in the radial and azimuthal direction, indicating that they were detected near the source region. In the wave spectrogram, discrete and “rising-tone” elements are found, suggesting that MS waves probably are a consequence of nonlinear wave-particle interaction.