THE COHERENCE SCALE LENGTH OF BAND-LIMITED PC3 PULSATIONS IN THE IONOSPHERE

Band-limited Pc-3 pulsations were observed on one day with pulsation m agnetometers, photometers and in VLF activity at South Pole and simult aneously, electric field pulsations were observed in the ionospheric c usp using the PACE HF-Radar located at Halley Station, Antarctica. The electric field pulsations were observed by the radar on open magnetic field lines, which were likely to be connected more directly to the s ource region (upstream of the foreshock) of the activity than the magn etic pulsations, which were observed on closed magnetic field lines. T he electric field pulsations were found to have a coherence scale leng th of around 30 - 60 km, significantly less than the upper limit that can be determined from magnetometer measurements.