The relative influence of H<sub>2</sub>O and CO<sub>2</sub> on the primitive surface conditions and evolution of rocky planets - Archive ouverte HAL Access content directly
Journal Articles Journal of Geophysical Research. Planets Year : 2017

The relative influence of H2O and CO2 on the primitive surface conditions and evolution of rocky planets

(1, 2) , (1) , (2) , (3) , (1) , (1)
1
2
3

Abstract

How the volatile content influences the primordial surface conditions of terrestrial planets, and thus, their future geodynamic evolution is an important question to answer. We simulate the secular convective cooling of a 1D magma ocean (“ MO”) in interaction with its outgassed atmosphere. The heat transfer in the atmosphere is computed either using the grey approximation or using a k-correlated method. We vary the initial CO2 and H2O contents (respectively from 0.1×10−2 to 14×10−2 wt% and from 0.03 to 1.4 times the Earth Ocean current mass (MEO)) and the solar distance - from 0.63 to 1.30 AU. A first rapid cooling stage, where efficient MO cooling and degassing take place, producing the atmosphere, is followed by a second quasi-steady-state where the heat flux balance is dominated by the solar flux. The end of the rapid cooling stage (“ ERCS”) is reached when the mantle heat flux becomes negligible compared to the absorbed solar flux. The resulting surface conditions at ERCS, including water ocean's formation, strongly depend both on the initial volatile content and solar distance D. For D > DC, the “ critical distance”, the volatile content controls water condensation and a new scaling law is derived for the water condensation limit. Although today's Venus is located beyond DC due to its high albedo, its high CO2/H2O ratio prevents any water ocean formation. Depending on the formation time of its cloud cover and resulting albedo, only 0.3 Earth ocean mass might be sufficient to form a water ocean on early Venus.
Fichier principal
Vignette du fichier
2017JE005286.pdf (7.44 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive
Loading...

Dates and versions

insu-01540209 , version 1 (18-11-2020)

Identifiers

Cite

A. Salvador, Hélène Massol, Anne Davaille, Emmanuel Marcq, Philippe Sarda, et al.. The relative influence of H2O and CO2 on the primitive surface conditions and evolution of rocky planets. Journal of Geophysical Research. Planets, 2017, 122 (7), pp.1458-1486. ⟨10.1002/2017JE005286⟩. ⟨insu-01540209⟩
97 View
115 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More