Simultaneous ground‐satellite observations of quasi‐periodic (QP) ELF‐VLF emissions near L=6

Simultaneous ground‐satellite observations of ELF‐VLF emissions have been carried out at Syowa station (L∼6) in Antarctica during the IMS period by receiving the telemetry signals from the ISIS 1 and 2 satellites. The quasi‐periodic intensity modulation of ELF‐VLF emissions at the satellite level, which had one‐to‐one correspondence with the intensity modulation of QP emissions at Syowa, was observed in the wide latitude range from −54° to −78° MLAT, and also in the region ∼2 hours apart from Syowa in magnetic local time. The spectral form of QP emissions observed on the ISIS satellite showed a clear dependence on latitude, i.e., emissions in the higher frequency range were observed at lower latitudes, while emissions in the lower frequency range were observed at higher latitudes. Although quasi‐periodic intensity modulation of polar chorus had generally one‐to‐one correspondence between the ground and satellite data, burst‐like discrete emissions did not show always one‐to‐one correspondence between both data. These results give a basis to confirm a phenomenological model proposed by Sato and Fukunishi [1981] for the generation mechanism of QP emissions.