Kitzmann, D.; Alibert, Y.; Godolt, M.; Grenfell, J. L.; Heng, K.; Patzer, A. B. C.; Rauer, H.; Stracke, B.; von Paris, P. (2015). The unstable CO₂ feedback cycle on ocean planets. Monthly notices of the Royal Astronomical Society, 452(4), pp. 3752-3758. Oxford University Press 10.1093/mnras/stv1487
|
Text
stv1487.pdf - Published Version Available under License Publisher holds Copyright. Download (785kB) | Preview |
Ocean planets are volatile-rich planets, not present in our Solar system, which are thought to be dominated by deep, global oceans. This results in the formation of high-pressure water ice, separating the planetary crust from the liquid ocean and, thus, also from the atmosphere. Therefore, instead of a carbonate–silicate cycle like on the Earth, the atmospheric carbon dioxide concentration is governed by the capability of the ocean to dissolve carbon dioxide (CO₂). In our study, we focus on the CO₂ cycle between the atmosphere and the ocean which determines the atmospheric CO₂ content. The atmospheric amount of CO₂ is a fundamental quantity for assessing the potential habitability of the planet's surface because of its strong greenhouse effect, which determines the planetary surface temperature to a large degree. In contrast to the stabilizing carbonate–silicate cycle regulating the long-term CO₂ inventory of the Earth atmosphere, we find that the CO₂ cycle feedback on ocean planets is negative and has strong destabilizing effects on the planetary climate. By using a chemistry model for oceanic CO₂ dissolution and an atmospheric model for exoplanets, we show that the CO₂ feedback cycle can severely limit the extension of the habitable zone for ocean planets.
Actions (login required)
 |
Edit item |