Observation of HF Plasma Wave Spectrum at Ionospheric Level Using Sounding Rocket S-210JA-21 in Antarctica (e. Event Session) (Proceedings of the Second Symposium on Coordinated Observations of the Ionosphere and the Magnetosphere in the Polar Regions : Part II)

An observation of the plasma wave spectrum in a high frequency range from 0.1 to 10 MHz has been made using the ionospheric sounding rocket S-210JA-21, launched on July 26, 1976 from Syowa Station in Antarctica. Plasma wave emissions were observed in two frequency ranges ; the first range is from the UHR frequency to the Z-mode cut ofr frequency, and the second is a range lower than the electron cyclotron frequency. The center frequency of the first kind emissions indicates a variation corresponding to the local upper hybrid and to the electron plasma frequencies along the flight path of S-210JA-21, indicating an evidence that the emissions are produced in the ionosphere as a result of the wave-particle interaction due to the auroral precipitation particles. The intensity of the second type emissions has been changed in correlation with the electron flux in the 40-60 keV range that is observed by ESH simultaneously. It has been clarified that the second kind emissions are plasma waves of the electrostatic origin which are also excited at the lower ionospheric level by the electrons precipitating along the auroral field line