Comparative Climates of TRAPPIST-1 planetary system: results from a simple climate-vegetation model

Abstract

The recent discovery of the planetary system hosted by the ultracool dwarf star TRAPPIST-1 could open new perspectives into the investigation of planetary climates of Earth-sized exoplanets, their atmospheres and their possible habitability. In this paper, we use a simple climate-vegetation energy-balance model to study the climate of the seven TRAPPIST-1 planets and the climate dependence on the global albedo, on the fraction of vegetation that could cover their surfaces and on the different greenhouse conditions. The model allows us to investigate whether liquid water could be maintained on the planetary surfaces (i.e., by defining a "surface water zone") in different planetary conditions, with or without the presence of greenhouse effect. It is shown that planet TRAPPIST-1d seems to be the most stable from an Earth-like perspective, since it resides in the surface water zone for a wide range of reasonable values of the model parameters. Moreover, according to the model outer planets (f, g and h) cannot host liquid water on their surfaces, even for Earth-like conditions, entering a snowball state. Although very simple, the model allows to extract the main features of the TRAPPIST-1 planetary climates.

arXiv comment5 figures, accepted on The Astrophysical Journal

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Cited by in corpus (11)

• Observing the Atmospheres of Known Temperate Earth-sized Planets with JWST
• Evolved Climates and Observational Discriminants for the TRAPPIST-1 Planetary System
• The Near-Infrared Transmission Spectra of TRAPPIST-1 Planets b, c, d, e, f, and g and Stellar Contamination in Multi-Epoch Transit Spectra
• Magma oceans and enhanced volcanism on TRAPPIST-1 planets due to induction heating
• Limits on Clouds and Hazes for the TRAPPIST-1 Planets
• Physical constraints for the evolution of life on exoplanets
• Cometary impactors on the TRAPPIST-1 planets can destroy all planetary atmospheres and rebuild secondary atmospheres on planets f, g, h
• Where can a Trappist-1 planetary system be produced?
• GJ357: A low-mass planetary system uncovered by precision radial-velocities and dynamical simulations
• Energy Dissipation in the Upper Atmospheres of Trappist-1 Planets
• Effect of vegetation on the temperatures of Trappist-1 planets