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Detailed Reference Information |
Baker, D.N., Feldman, W.C., Gary, S.P., McComas, D.J. and Middleditch, J. (1986). Plasma fluctuations and large-scale mixing near comet Giacobini-Zinner. Geophysical Research Letters 13: doi: 10.1029/GL013i003p00271. issn: 0094-8276. |
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Low-pass filtered data from the ICE electron spectrometer are used to examine relationships between plasma densities, flow speeds, flow directions, and temperatures at distances within ~105 km of the Comet Giacobini-Zinner nucleus. The sheath/transition region is characterized by electron temperatures of ~4¿105 K but with flow speeds and densities that commonly vary by factors of three or more. The largest amplitude density spikes often have significant flow changes associated with them, but a consistent pattern (as might accompany cometary rays, for example) is not found. Power spectral analyses in and near the sheath/transition regions show that density fluctuation levels are enhanced by all detectable frequencies from ~0 to 21 mHz, consistent with strong density fluctuations on all measured time scales. Marginally significant power peaks are seen at periods of ~4 min on the inbound pass and at ~2 min on the outbound pass. Mechanisms such as amplification of convected ion pick-up waves and cometary rays for producing the large plasma variations are discussed. It is also suggested that a Rayleigh-Taylor driven mixing mechanism at a mass loading boundary ~105 km from the nucleus may be operative. |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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