PARAMETRIC EXCITATION OF ELECTROSTATIC ION CYCLOTRON WAVES IN THE AURORAL ZONE

Parametric process in which lower hybrid wave decays into electrostatic ion cyclotron wave and whistler wave in the auroral zone is analysed.The results show that,with the wave amplitude of the pump from 40 mV/m to 100 mV/m,the growth rate of the excited electrostatic ion cyclotron wave can reach 0.2-0.5 ω_ci,which is larger than the expected values by such linear mechanisms as current-driven instability and ion-beam instability.Therefore,when the amplitude of the pump is larger than 40 mV/m,the parametric excitation of electrostatic ion cyclotron wave may be the dominant mechanism.