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| Titel |
Planetary-scale waves and the meteorology of Titan's tropics |
| VerfasserIn |
J. Mitchell, M. Adamkovics, R. Caballero, E. Turtle |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250070215
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| Zusammenfassung |
| Titan exhibits an active weather cycle involving methane. Equatorial and mid-latitude clouds
can be organized into fascinating morphologies on scales exceeding 1,000 km. Observations
include an arrow-shaped equatorial cloud that produced detectable surface accumulation,
probably from the precipitation of liquid methane. An analysis of an earlier cloud outburst
indicated an interplay between high- and low-latitude cloud activity, mediated by
planetary-scale atmospheric waves. We present a combined analysis of cloud observations
and simulations with a three-dimensional general circulation model of Titan’s atmosphere
providing a physical interpretation of observed storms, their relation to atmosphere dynamics
and their aggregate effect on surface erosion. We find that planetary-scale Kelvin waves arise
naturally in our simulations, and robustly organize convection into chevron-shaped
storms at the equator during the equinoctial season. A second and much slower
wave mode organizes convection into southern-hemisphere streaks oriented in a
northwest–southeast direction, similar to observations. As a result of the phasing of these
modes, precipitation rates can be as high as twenty times the local average in our
simulations, possibly playing a crucial role in fluvial erosion of Titan’s surface.
We also present a forecast of the weather expected in the coming season on Titan. |
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