CONDITIONS FOR OCEANS ON EARTH-LIKE PLANETS ORBITING WITHIN THE HABITABLE ZONE: IMPORTANCE OF VOLCANIC CO<sub>2</sub>DEGASSING

Kadoya, Shintaro; Tajika, Eiichi

doi:10.1088/0004-637x/790/2/107

Cited by 63 publications

(80 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Kadoya & Tajika 2014Foley & Driscoll 2016). From the point of view of modelling of the interior, the most important difference between our approach and those above is that we assume our planet to operate in a stagnant-lid mode of convection rather than in the mobile-lid (or active-lid) mode realized through plate tectonics.…”

Section: Discussionmentioning

confidence: 99%

“…On the one hand, even the Earth, where plate tectonics and a carbon-silicate cycle are active, could become uninhabitable by turning into a snowball if the degassing rate of CO 2 from the interior becomes too low (Tajika 2007;Kadoya & Tajika 2014. On the other hand, the very way in which plate tectonics operates on Earth, when it started, and whether it is a stable or a transient feature in the tectonic history of our planet are all complex and still controversial matters (e.g.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The habitability of a stagnant-lid Earth

Tosi

Godolt

Stracke

et al. 2017

A&A

128

View full text Add to dashboard Cite

Context. Plate tectonics is considered a fundamental component for the habitability of the Earth. Yet whether it is a recurrent feature of terrestrial bodies orbiting other stars or unique to the Earth is unknown. The stagnant lid may rather be the most common tectonic expression on such bodies. Aims. To understand whether a stagnant-lid planet can be habitable, i.e. host liquid water at its surface, we model the thermal evolution of the mantle, volcanic outgassing of H 2 O and CO 2 , and resulting climate of an Earth-like planet lacking plate tectonics. Methods. We used a 1D model of parameterized convection to simulate the evolution of melt generation and the build-up of an atmosphere of H 2 O and CO 2 over 4.5 Gyr. We then employed a 1D radiative-convective atmosphere model to calculate the global mean atmospheric temperature and the boundaries of the habitable zone (HZ).Results. The evolution of the interior is characterized by the initial production of a large amount of partial melt accompanied by a rapid outgassing of H 2 O and CO 2 . The maximal partial pressure of H 2 O is limited to a few tens of bars by the high solubility of water in basaltic melts. The low solubility of CO 2 instead causes most of the carbon to be outgassed, with partial pressures that vary from 1 bar or less if reducing conditions are assumed for the mantle to 100-200 bar for oxidizing conditions. At 1 au, the obtained temperatures generally allow for liquid water on the surface nearly over the entire evolution. While the outer edge of the HZ is mostly influenced by the amount of outgassed CO 2 , the inner edge presents a more complex behaviour that is dependent on the partial pressures of both gases. Conclusions. At 1 au, the stagnant-lid planet considered would be regarded as habitable. The width of the HZ at the end of the evolution, albeit influenced by the amount of outgassed CO 2 , can vary in a non-monotonic way depending on the extent of the outgassed H 2 O reservoir. Our results suggest that stagnant-lid planets can be habitable over geological timescales and that joint modelling of interior evolution, volcanic outgassing, and accompanying climate is necessary to robustly characterize planetary habitability.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The habitability of a stagnant-lid Earth

Tosi

Godolt

Stracke

et al. 2017

A&A

128

View full text Add to dashboard Cite

show abstract

“…At the outer edge, the models assume the regulation of the climate by the carbonate-silicate cycle. Recent calculations have suggested that planets in the outer regions of the HZ may be less likely to maintain stable, warm climates, but instead may oscillate between long, globally glaciated states and shorter periods of climatic warmth (Kadoya & Tajika 2014, 2015Menou et al 2015;Haqq-Misra et al 2016). Such conditions, similar to "Snowball Earth" episodes experienced on Earth, would be detrimental to the development of complex land life.…”

Section: Discussionmentioning

confidence: 99%

Habitable Zone Boundaries for Circumbinary Planets

Cukier¹,

Kopparapu²,

Kane³

et al. 2019

PASP

View full text Add to dashboard Cite

We use a one-dimensional (1-D) cloud-free climate model to estimate habitable zone (HZ) boundaries for terrestrial planets of masses 0.1 M E and 5 M E around circumbinary stars of various spectral type combinations. Specifically, we consider binary systems with host spectral types -M and M-M. Scaling the background N 2 atmospheric pressure with the radius of the planet, we find that the inner edge of the HZ moves inwards towards the star for 5 M E compared to 0.1 M E planets for all spectral types. This is because the water-vapor column depth is smaller for larger planets and higher temperatures are needed before water vapor completely dominates the outgoing longwave radiation. The outer edge of the HZ changes little due to competing effects of the albedo and greenhouse effect. While these results are broadly consistent with the trend of single star HZ results for different mass planets, there are significant differences between single star and binary star systems for the inner edge of the HZ. Interesting combinations of stellar pairs from our 1-D model results can be used to explore for in-depth climate studies with 3-D climate models. We identify a common HZ stellar flux domain for all circumbinary spectral types.

show abstract

“…Snowball Earth events are an acute stressor on life, but may actually increase the complexity of life through evolutionary pressure (Kirschvink 1992;Hoffman et al 1998) and by increasing the atmospheric oxygen concentration (Hoffman & Schrag 2002;Laakso & Schrag 2014, 2017 that might act as biosignatures to remote astronomers. Moreover, planets in the habitable zone with low levels of CO 2 outgassing may experience limit cycles between habitable and snowball climate states (Kadoya & Tajika 2014;Menou 2015;Haqq-Misra et al 2016;Batalha et al 2016;Abbot 2016;Paradise & Menou 2017). It is therefore important to understand the transitions into and out of snowball events for tidally locked planets.…”

Section: Introductionmentioning

confidence: 99%

No Snowball on Habitable Tidally Locked Planets

Checlair

Menou

Abbot

2017

ApJ

100

View full text Add to dashboard Cite

The TRAPPIST-1, Proxima Centauri, and LHS 1140 systems are the most exciting prospects for future follow-up observations of potentially inhabited planets. All orbit nearby M-stars and are likely tidally locked in 1:1 spinorbit states, which motivates the consideration of the effects that tidal locking might have on planetary habitability. On Earth, periods of global glaciation (snowballs) may have been essential for habitability and remote signs of life (biosignatures) because they are correlated with increases in the complexity of life and in the atmospheric oxygen concentration. In this paper we investigate the snowball bifurcation (sudden onset of global glaciation) on tidally locked planets using both an energy balance model and an intermediate-complexity global climate model. We show that tidally locked planets are unlikely to exhibit a snowball bifurcation as a direct result of the spatial pattern of insolation they receive. Instead they will smoothly transition from partial to complete ice coverage and back. A major implication of this work is that tidally locked planets with an active carbon cycle should not be found in a snowball state. Moreover, this work implies that tidally locked planets near the outer edge of the habitable zone with low CO 2 outgassing fluxes will equilibrate with a small unglaciated substellar region rather than cycling between warm and snowball states. More work is needed to determine how the lack of a snowball bifurcation might affect the development of life on a tidally locked planet.

show abstract

CONDITIONS FOR OCEANS ON EARTH-LIKE PLANETS ORBITING WITHIN THE HABITABLE ZONE: IMPORTANCE OF VOLCANIC CO₂DEGASSING

Cited by 63 publications

References 27 publications

The habitability of a stagnant-lid Earth

The habitability of a stagnant-lid Earth

Habitable Zone Boundaries for Circumbinary Planets

No Snowball on Habitable Tidally Locked Planets

Contact Info

Product

Resources

About

CONDITIONS FOR OCEANS ON EARTH-LIKE PLANETS ORBITING WITHIN THE HABITABLE ZONE: IMPORTANCE OF VOLCANIC CO2DEGASSING

Cited by 63 publications

References 27 publications

The habitability of a stagnant-lid Earth

The habitability of a stagnant-lid Earth

Habitable Zone Boundaries for Circumbinary Planets

No Snowball on Habitable Tidally Locked Planets

Contact Info

Product

Resources

About

CONDITIONS FOR OCEANS ON EARTH-LIKE PLANETS ORBITING WITHIN THE HABITABLE ZONE: IMPORTANCE OF VOLCANIC CO₂DEGASSING