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Titel |
South polar dynamics of the Venusian atmosphere from VIRTIS/Venus Express mapping in the thermal range |
VerfasserIn |
David Luz, David Berry, Javier Peralta, Pierre Drossart, Giuseppe Piccioni |
Konferenz |
EGU General Assembly 2010
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 12 (2010) |
Datensatznummer |
250041454
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Zusammenfassung |
We report on measurements of Venus cloud velocities from VIRTIS/Venus Express
observations of the south polar region of Venus. Cloud tracking has been performed using a
method of automated digital correlation. Tracking has been performed on pairs of
monochromatic VIRTIS images selected mainly in the 5 μm window, but also at 1.74, 2.3,
3.93 micrometers. Wind measurements from vector retrievals based on automated feature
tracking show high variability, indicating the presence of important transient motions. The
time-averaged zonal winds indicate different day and night side regimes. On the day side
both the zonal wind component (u) and the meridional one (v) are approximately
uniform between 84S and 76S, with u ~-40Â m/s and v ~-10Â m/s. On the night
side the zonal wind decreases poleward, from a maximum at 76S. The meridional
wind is smaller than on the day side and appears to change sign from poleward to
equatorward at 76S. The cold collar boundary appears to be a transition region not
only for the temperature, but for the winds as well. In this region wave motions are
also apparent, with amplitudes on the order of 40 m/s for u′ and 10 m/s for v′. |
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