Greater climate sensitivity and variability on TRAPPIST-1e than Earth

Abstract

The atmospheres of rocky exoplanets are close to being characterized by astronomical observations, in part due to the commissioning of the James Webb Space Telescope. These observations compel us to understand exoplanetary atmospheres, in the voyage to find habitable planets. With this aim, we investigate the effect that CO${}_2$ partial pressure (pCO${}_2$) has on exoplanets' climate variability, by analyzing results from ExoCAM model simulations of the tidally locked TRAPPIST-1e exoplanet, an Earth-like aqua-planet and Earth itself. First, we relate the differences between the planets to their elementary parameters. Then, we compare the sensitivity of the Earth analogue and TRAPPIST-1e's surface temperature and precipitation to pCO${}_2$. Our simulations suggest that the climatology and extremes of TRAPPIST-1e's temperature are $\sim$1.5 times more sensitive to pCO${}_2$ relative to Earth. The precipitation sensitivity strongly depends on the specific region analyzed. Indeed, the precipitation near mid-latitude and equatorial sub-stellar regions of TRAPPIST-1e is more sensitive to pCO${}_2$, and the precipitation sensitivity is $\sim$2 times larger in TRAPPIST-1e. A dynamical systems perspective, which provides information about how the atmosphere evolves in phase-space, provides additional insights. Notably, an increase in pCO${}_2$, results in an increase in atmospheric persistence on both planets, and the persistence of TRAPPIST-1e is more sensitive to pCO${}_2$ than Earth. We conclude that the climate of TRAPPIST-1e may be more sensitive to pCO${}_2$, particularly on its dayside. This study documents a new pathway for understanding the effect that varying planetary parameters have on the climate variability of potentially habitable exoplanets and on Earth.

Accepted at ApJ

References in corpus (13)

• The Detectability and Characterization of the TRAPPIST-1 Exoplanet Atmospheres with JWST
• Asynchronous rotation of Earth-mass planets in the habitable zone of lower-mass stars
• Atmospheric dynamics of terrestrial exoplanets over a wide range of orbital and atmospheric parameters
• K-H_2 Quasi-molecular absorption detected in the T-dwarf epsilon Indi Ba
• Impact of Clouds and Hazes on the Simulated JWST Transmission Spectra of Habitable Zone Planets in the TRAPPIST-1 System
• The atmospheric circulation and climate of terrestrial planets orbiting Sun-like and M-dwarf stars over a broad range of planetary parameters
• Hot Jupiter Variability in Eclipse Depth
• Ocean Dynamics and the Inner Edge of the Habitable Zone for Tidally Locked Terrestrial Planets
• Temporal Variability in Hot Jupiter Atmospheres
• Formation and dynamics of water clouds on temperate sub-Neptunes: The example of K2-18b
• Effects of Radius and Gravity on the Inner Edge of the Habitable Zone
• Possible substellar companions in dwarf eclipsing binaries: SDSS J143547.87+373338.5, NSVS 7826147, and NSVS 14256825
• Climates of Warm Earth-Like Planets III: Fractional Habitability from a Water Cycle Perspective

Cited by in corpus (3)

• Stratospheric dayside-to-nightside circulation drives the 3-D ozone distribution on synchronously rotating rocky exoplanets
• Traveling planetary-scale waves cause cloud variability on tidally locked aquaplanets
• Chemistry, Climate, and Transmission Spectra of TRAPPIST-1 e Explored with a Multimodel Sparse Sampled Ensemble