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| Titel |
New results from the Oxford Venus GCM |
| VerfasserIn |
Joao Mendonca, Peter Read, Stephen Lewis, Christopher Lee |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250045959
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| Zusammenfassung |
| Venus models are at the stage of evolving from simplified General Circulation Models
(SGCM) towards more complete and physically-based ones. The process is complex and
challenging due to difficulties in reproducing the physical and dynamical conditions in the
global atmosphere of Venus in a realistic numerical approach. The circulation of Venus’
atmosphere is well known to exhibit strong super rotation and a variety of enigmatic features
which remain poorly understood.
Here we present a new version of our Venus GCM that uses a complex radiation scheme
for solar and thermal spectra interacting with time-variable cloud cover. This new radiative
parameterisation is more complete than previous works (Lebonnois et al 2010;
Yamamoto et al. 2010), and uses different approaches in the two main wavelength bands:
solar radiation (0.1-5.5μm) and thermal radiation (1.7-250 μm). The solar radiation
calculation is based on the δ-Eddington approximation (two-stream-type), with
an adding layer method and a correlated k-distribution that represents absorption
and scattering of sunlight by gas molecules and aerosols. For the thermal radiation
case, we use a code based on an absorptivity/emissivity formulation (neglecting
scattering).
Our Venus GCM uses the new radiation codes in conjunction with the cloud transport
model implemented by Lee 2006 and Lee et al 2010. These features allow the time variability
in the cloud to interact with the radiative budget calculation.
In the poster that we are presenting, we will show some preliminary results of our Venus
GCM using this new radiative-cloud variability parameterisation, including a brief schematic
explanation of this new formulation.
Bibliography
S. Lebonnois, F. Hourdin, V. Eymet, A. Crespin, R. Fournier, and F. Forget;
Superrotation of Venus’ atmosphere analyzed with a full general circulation
model; Journal of Geophysical Research (Planets); June 2010
C. Lee; Modelling of the Atmosphere of Venus; PhD thesis; PhD Thesis; Oxford
University; 2006
C. Lee, S. R. Lewis, and P. L. Read; A bulk cloud parameterization in a Venus
General Circulation Model; Icarus; April 2010
M. Yamamoto, M Takahashi, K. Ikeda, M. Takahashi, and Y. Matsuda;
Development of Venus GCM toward the AKATSUKI mission; 2010 VEXAG
International Workshop; 2010 |
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