HF Doppler Sounding Experiment in Japan - HFDOPE

Since 2003, an HF Doppler sounding experiment has been conducted in Japan for the studies of atmosphere, ionosphere and magnetosphere. Currently, 1 transmitting station and 11 receiving stations are operative by a collaborative effort of five different research institutes. Multiple frequency sounding of the ionosphere enables us to observe the variations at different altitudes in a simultaneous manner.

The scientific targets of the experiment include:

1. Ionospheric dynamics
   • Sporadic E-layer (Es)
   • Medium-scale traveling ionospheric disturbances (MSTIDs) and atmospheric gravity waves (AGWs)
   • Large-scale traveling ionospheric disturbances (LSTIDs)
2. Magnetosphere-Ionosphere coupling (M-I coupling)
   • Global-scale electric field variation (penetration from the magnetosphere)
   • Sudden Commencement (SC) due to the solar wind pressure pulse
   • ULF pulsations (Pc3 - Pc5) at mid-latitudes
3. Vertical coupling in the Atmosphere-Ionosphere system (vertical coupling)
   • Ionospheric variation after large earthquakes/tsunamis
   • Ionospheric variation after volcanic eruptions/typhoons

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