|
|
 |
|
|
Ann. Geophys., 22, 2337-2344, 2004
www.ann-geophys.net/22/2337/2004/
© European Geosciences Union 2004
Statistical behavior of foreshock Langmuir waves observed by the Cluster wideband data plasma wave receiver
K. Sigsbee1, C. A. Kletzing1, D. A. Gurnett1, J. S. Pickett1, A. Balogh2, and E. Lucek2
1Department of Physics and Astronomy, 203 Van Allen Hall, University of Iowa, Iowa City, IA 52242, USA
2Space and Atmospheric Physics Group, The Blackett Laboratory, Imperial College, Prince Consort Road, London, SW7 2BW, UK
Abstract. We present the statistics of Langmuir wave amplitudes in the Earth's
foreshock using Cluster Wideband Data (WBD) Plasma Wave Receiver electric
field waveforms from spacecraft 2, 3 and 4 on 26 March 2002. The largest
amplitude Langmuir waves were observed by Cluster near the boundary between
the foreshock and solar wind, in agreement with earlier studies. The
characteristics of the waves were similar for all three spacecraft,
suggesting that variations in foreshock structure must occur on scales
greater than the 50-100km spacecraft separations. The electric field
amplitude probability distributions constructed using waveforms from the
Cluster WBD Plasma Wave Receiver generally followed the log-normal statistics
predicted by stochastic growth theory for the event studied. Comparison with
WBD receiver data from 17 February 2002, when spacecraft 4 was set in a
special manual gain mode, suggests non-optimal auto-ranging of the instrument
may have had some influence on the statistics.
Full Article in PDF (255 KB) |
|
|
