 |
| Titel |
CIDGA - Coupling of Interior Dynamic models with Global Atmosphere models |
| VerfasserIn |
Lena Noack, Ana-Catalina Plesa, Doris Breuer |
| Konferenz |
EGU General Assembly 2010
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250039994
|
|
|
|
|
|
| Zusammenfassung |
| Atmosphere temperatures and in particular the surface temperatures mostly depend on the
solar heat flux and the atmospheric composition. The latter can be influenced by interior
processes of the planet, i.e. volcanism that releases greenhouse gases such as H2O, CO2 and
methane into the atmosphere and plate tectonics through which atmospheric CO2 is recycled
via carbonates into the mantle. An increasing concentration of greenhouse gases in the
atmosphere results in an increase of the surface temperature. Changes in the surface
temperature on the other hand may influence the cooling behaviour of the planet and hence
influence its volcanic activity [Phillips et al., 2001]. This feedback relation between mantle
convection and atmosphere is not very well understood, since until now mostly either the
interior dynamic of a planet or its atmosphere was investigated separately. 2D or 3D mantle
convection models to the authors’ knowledge haven’t been coupled to the atmosphere so
far.
We have used the 3D spherical simulation code GAIA [Hüttig et al., 2008] including partial
melt production and coupled it with the atmosphere module CIDGA using a gray greenhouse
model for varying H2O concentrations. This way, not only the influence of mantle dynamics
on the atmosphere can be investigated, but also the recoupling effect, that the surface
temperature has on the mantle dynamics. So far, we consider one-plate planets without
crustal and thus volatile recycling. Phillips et al. [2001] already investigated the
coupling effect of the surface temperature on mantle dynamics by using simple
parameterized convection models for Venus. In their model a positive feedback
mechanism has been observed, i.e., an increase of the surface temperature leads to an
increase of partial melt and hence an increase of atmosphere density and surface
temperature.
Applying our model to Venus, we show that an increase of surface temperature leads not only
to an increase of partial melt in the mantle; it also strongly influences the style of mantle
convection. As a consequence, the positive feedback processes as suggested by Phillips et al
[2001] is not predicted in our model for all cases in particular when the surface temperature is
very high and reaches a critical value for which convection turns from a stagnant lid regime in
a sluggish-like regime.
References
C. Hüttig and K. Stemmer (2008), PEPI.
R.J. Phillips, M.A. Bullock, and S.A. Hauck, II (2001), GRL. |
|
|
|
|
|
|