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| It was planned by the National Institute of Polar Research (NIPR) to launch successively from Syowa Station three balloons with identical instrumentation with a spatial separation of ~150 km, in order to study spatial and temporal variations of the phenomena occurring in the boundary regions in the magnetosphere. Onboard instruments are ULF/ELF/VLF wave receiver, aurora X-ray imager, DC electric field instrument, 3-axis fluxgate magnetometer, and the ionospheric total electron content measurement using GPS. The wave instrument measures a magnetic component with a big loop antenna surrounding the balloon itself (40m in diameter). The instrument measures waveform in 0.2-4.0 Hz band, wave intensities at 300, 600, 1200 and 2400 Hz with a sampling rate of 2Hz, and a rough spectrum (5, 10, 20 and 36 kHz) with a sweep period of 5s. The Project Manager is Prof. H. Yamagishi ( yamagisi@uap.nipr.ac.jp). |
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| The first balloon, PPB No.9, was launched on 6 January, but the flight was terminated 2 hours after the launch due to a trouble in the cut-down command system. After a week of waiting, PPB No.8 and 10 were launched successfully at 06:49 and 12:16 UT on 13th January. The balloons reached a ceiling altitude of 32 km and moved westward at a speed of about 20 km/h. When they traveled halfway round the Antarctica on 25 January, the wind system in the stratosphere has changed directions. PPB No.8 was stagnated there for a week, while PPB No.10 moved towards lower latitudes, and dropped on the ocean 300 km offshore of Patagonia on 31 January 2003. After a week of stagnation, PPB No.8 started to move towards lower latitudes on 31 January, and dropped on the ocean 500 km offshore of Patagonia on 7 February. Trajectory of the balloon is shown in the PPB home page: http://ppb.nipr.ac.jp. |
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During these flights, the balloons traversed magnetic latitude range of
50-70 degrees, and the separation of the balloons changed from 150km to
about 1500km. Observed data were directly transferred to Japan by Iridium
satellite telephone system, as well as telemetered to the ground at
Rothera Station in Antarctic Peninsula. The wave instrument onboard
observed Pc1 pulsations, ELF hiss, polar chorus and auroral hiss. Daily
summary of the wave observation can be seen in
http://ppb.nipr.ac.jp.
Some of the wave phenomena were observed simultaneously, and some were
not by the two balloons, reflecting spatial extent of the phenomena.
Pc1 pulsations consisted of transient bursts with decreasing amplitude
lasting for ~20s, and continuous type emissions lasting for more than 10
minutes. Example of this waveform can be seen in the PPB home page.
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| By courtesy of Prof. H. Yamagishi. |
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