Datasets of coupled exoplanet interior-atmosphere evolutions for the manuscript "Water oceans on high-density stagnant-lid planets". planet_evolutions directory contains the main data from the study, validations_1Me contains supplementary validation studies evaluating the model sensitivity with respect to changing model parameters. These runs focus on planets with one Earth mass. Each file in the raw_data directoriescontains a full interior and atmosphere evolution of a single planet. The initial parameters are given in the header of each CSV file. The evolution_snapshots.csv files contain snapshots of those planets at random times.
Ever since the discovery of sub-Neptunes, exoplanets with masses < 20 M⊕ and radii < 4 R⊕, they have presented a distinct challenge in the exoplanet modelling community. When plotted on a mass-radius diagram, their bulk densities lie in a range spanning from that of pure iron to less than water. Such bulk densities are not necessarily indicative of the interior structure within, and when characterized using interior models the results are often varied in their morphology and highly degenerate.  A semi-grey pressure-temperature profile approximation for an atmosphere is a popular choice in Interior-Atmosphere modelling as could allow us to estimate the radius contribution of an atmosphere as well as a full radiative transfer line-by-line model, but without the computational cost of a full 1-D radiative convective climate-chemistry model. Since the parameter space is large, thousands of interior-atmosphere model runs are required in order to quantify the potential degeneracies. Nevertheless, while the semi-grey approximation treats the problem in a more simplified manner than other more robust methods, which allows for faster analytical calculations, there are still underdetermined factors which make choosing the most appropriate value difficult without more data (e.g. atmospheric spectra and profiles).  In this talk I will explore the impact of the different ways one chooses the value of one factor, the mean-opacity (𝜅). As this is a function of the stellar and planetary radiation wavelengths, it has an effect on not only the atmospheric and planetary profiles, but also the range of characterization solutions and their degeneracies therein. To highlight these differences, I will be focussing on two real-world test cases: GJ 1214 b and K2-18 b, at two different atmospheric compositions (1x and 50x solar metallicity). By comparing the atmosphere profiles and the range of solutions from interior modelling, both within the parameter range and to values in literature, we will quantify the impact on planetary characterization and develop a more systematic method for future models.
Abstract Many super‐Earths are on very short orbits around their host star and, therefore, more likely to be tidally locked. Because this locking can lead to a strong contrast between the dayside and nightside surface temperatures, these super‐Earths could exhibit mantle convection patterns and tectonics that could differ significantly from those observed in the present‐day solar system. The presence of an atmosphere, however, would allow transport of heat from the dayside toward the nightside and thereby reduce the surface temperature contrast between the two hemispheres. On rocky planets, atmospheric and geodynamic regimes are closely linked, which directly connects the question of atmospheric thickness to the potential interior dynamics of the planet. Here, we study the interior dynamics of super‐Earth GJ 486b ( , , K), which is one of the most suitable M‐dwarf super‐Earth candidates for retaining an atmosphere produced by degassing from the mantle and magma ocean. We investigate how the geodynamic regime of GJ 486b is influenced by different surface temperature contrasts by varying possible atmospheric circulation regimes. We also investigate how the strength of the lithosphere affects the convection pattern. We find that hemispheric tectonics, the surface expression of degree‐1 convection with downwellings forming on one hemisphere and upwelling material rising on the opposite hemisphere, is a consequence of the strong lithosphere rather than surface temperature contrast. Anchored hemispheric tectonics, where downwellings und upwellings have a preferred (day/night) hemisphere, is favored for strong temperature contrasts between the dayside and nightside and higher surface temperatures.
Little is known about the early evolution of Venus and a potential habitable period during the first one billion years. In particular, it remains unclear whether or not plate tectonics and an active carbonate-silicate cycle were present. In the presence of liquid water but without plate tectonics, weathering would have been limited to freshly produced basaltic crust, with an early carbon cycle restricted to the crust and atmosphere. With the evaporation of surface water, weathering would cease. With ongoing volcanism, carbonate sediments would be buried and sink downwards. Thereby, carbonates would heat up until they become unstable and the crust would become depleted in carbonates. With CO$_2$ supply to the atmosphere the surface temperature rises further, the depth below which decarbonation occurs decreases, causing the release of even more CO$_2$. We assess the habitable period of an early stagnant-lid Venus by employing a coupled interior-atmosphere evolution model accounting for CO$_2$ degassing, weathering, carbonate burial, and crustal decarbonation. We find that if initial surface conditions allow for liquid water, weathering can keep the planet habitable for up to 900 Myr, followed by evaporation of water and rapid crustal carbonate depletion. For the atmospheric CO$_2$ of stagnant-lid exoplanets, we predict a bimodal distribution, depending on whether or not these planets experienced a runaway greenhouse in their history. Planets with high atmospheric CO$_2$ could be associated with crustal carbonate depletion as a consequence of a runaway greenhouse, whereas planets with low atmospheric CO$_2$ would indicate active silicate weathering and thereby a habitable climate.
Datasets of coupled exoplanet interior-atmosphere evolutions for the manuscript "Water oceans on high-density stagnant-lid planets". planet_evolutions directory contains the main data from the study, validations_1Me contains supplementary validation studies evaluating the model sensitivity with respect to changing model parameters. These runs focus on planets with one Earth mass. Each file in the raw_data directoriescontains a full interior and atmosphere evolution of a single planet. The initial parameters are given in the header of each CSV file. The evolution_snapshots.csv files contain snapshots of those planets at random times.
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