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| Titel |
Density waves in Titan's upper atmosphere |
| VerfasserIn |
Jun Cui, Roger Yelle, Tao Li, Yuan Lian, Ingo Mueller-Wodarg, Darci Snowden |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250087399
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| Publikation (Nr.) |
 EGU/EGU2014-1443.pdf |
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| Zusammenfassung |
| Analysis of the Cassini Ion Neutral Mass Spectrometer data reveals the omnipresence of
density waves in various constituents of Titan’s upper atmosphere, with quasi-periodical
structures visible for N2, CH4, 29N2 and some of the minor constituents. The N2 amplitude
lies in the range of - 4%-16% with a mean of - 8%. Compositional variation is clearly seen
as a sequence of decreasing amplitude with increasing scale height. The observed vertical
variation of amplitude implies significant wave dissipation in different constituents, possibly
contributed by molecular viscosity for N2 but by both molecular viscosity and binary
diffusion for the others. A wave train with near horizontally propagating wave energy and
characterized by a wavelength of - 730km and a wave period of - 10hr is found to
best reproduce various aspects of the observations in a globally averaged sense.
Some horizontal and seasonal trends in wave activity are identified, suggesting a
connection between the mechanism driving the overall variability in the background
atmosphere and the mechanism driving the waves. No clear association of wave
activity with magnetospheric particle precipitation can be identified from the data. |
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