Stratosphere circulation on tidally locked ExoEarths

Abstract

Stratosphere circulation is important to interpret abundances of photo-chemically produced compounds like ozone that we aim to observe to assess habitability of exoplanets. We thus investigate a tidally locked ExoEarth scenario for TRAPPIST-1b, TRAPPIST-1d, Proxima Centauri~b and GJ 667 C~f with a simplified 3D atmosphere model and for different stratospheric wind breaking assumptions. These planets are representatives for different circulation regimes for orbital periods: $P_{orb}=1-100$~days. The circulation of exoplanets with $P_{orb}\le$ 25~days can be dominated by the standing tropical Rossby wave in the troposphere and also in the stratosphere: It leads to a strong equatorial eastward wind jet and to 'Anti-Brewer-Dobson'-circulation that confines air masses to the stratospheric equatorial region. Thus, the distribution of photo-chemically produced species and aerosols may be limited to an 'equatorial transport belt'. In contrast, planets with $P_{orb}>25$~days, like GJ~667~C~f, exhibit efficient thermally driven circulation in the stratosphere that allows for a day side-wide distribution of air masses. The influence of the standing tropical Rossby waves on tidally locked ExoEarths with $P_{orb}\le 25$~days can, however, be circumvented with deep stratospheric wind breaking alone - allowing for equator-to-pole transport like on Earth. For planets with $3\le P_{orb}\le 6$~days, the extratropical Rossby wave acts as an additional safe-guard against the tropical Rossby wave in case of shallow wind breaking. Therefore, TRAPPIST-1d is less prone to have an equatorial transport belt in the stratosphere than Proxima~Centauri~b. Even our Earth model shows an equatorial wind jet, if stratosphere wind breaking is inefficient.

arXiv comment14 pages, 13 figures

References in corpus (35)

• Habitable Zones Around Main-Sequence Stars: New Estimates
• Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
• A terrestrial planet candidate in a temperate orbit around Proxima Centauri
• Temperate Earth-sized planets transiting a nearby ultracool dwarf star
• Biosignatures from Earth-Like Planets Around M Dwarfs
• The Effect of a Strong Stellar Flare on the Atmospheric Chemistry of an Earth-like Planet Orbiting an M dwarf
• Equatorial superrotation on tidally locked exoplanets
• Stabilizing Cloud Feedback Dramatically Expands the Habitable Zone of Tidally Locked Planets
• A dynamically-packed planetary system around GJ667C with three super-Earths in its habitable zone
• A seven-planet resonant chain in TRAPPIST-1
• A temperate rocky super-Earth transiting a nearby cool star
• Strong Dependence of the Inner Edge of the Habitable Zone on Planetary Rotation Rate
• Water loss from Earth-sized planets in the habitable zones of ultracool dwarfs: Implications for the planets of TRAPPIST-1
• Transiting exoplanets from the CoRoT space mission VI. CoRoT-Exo-3b: The first secure inhabitant of the brown-dwarf desert
• Assessing the Habitability of the TRAPPIST-1 System Using a 3D Climate Model
• Habitable Moist Atmospheres On Terrestrial Planets Near the Inner Edge Of the Habitable Zone Around M-dwarfs
• Modelling climate diversity, tidal dynamics and the fate of volatiles on TRAPPIST-1 planets
• The UV and X-ray activity of the M dwarfs within 10pc of the Sun
• Frequent flaring in the TRAPPIST-1 system - unsuited for life?
• Habitable worlds with JWST: transit spectroscopy of the TRAPPIST-1 system?
• Atmospheric dynamics of brown dwarfs and directly imaged giant planets
• Towards the Minimum Inner Edge Distance of the Habitable Zone
• Exploring the climate of Proxima B with the Met Office Unified Model
• UV Surface Habitability of the TRAPPIST-1 System
• Connecting the dots II: Phase changes in the climate dynamics of tidally locked terrestrial exoplanets
• The HARPS search for southern extra-solar planets XXXV. Super-Earths around the M-dwarf neighbors Gl433 and Gl667C
• Prospects for Characterizing the Atmosphere of Proxima Centauri b
• Influence of Stellar Flares on the Chemical Composition of Exoplanets and Spectra
• Sensitivity of Biosignatures on Earth-like Planets orbiting in the Habitable Zone of Cool M-Dwarf Stars to varying Stellar UV Radiation and Surface Biomass Emissions
• Connecting the dots: A versatile model for the atmospheres of tidally locked Super-Earths
• The density of mid-sized Kuiper belt objects from ALMA thermal observations
• Connecting the dots III: Night side cooling and surface friction affect climates of tidally locked terrestrial planets
• Updated Masses for the TRAPPIST-1 Planets
• Magnetic properties of Proxima Centauri b analogues

Cited by in corpus (31)

• Impact of Clouds and Hazes on the Simulated JWST Transmission Spectra of Habitable Zone Planets in the TRAPPIST-1 System
• Habitable Climate Scenarios for Proxima Centauri b With a Dynamic Ocean
• Persistence of Flare-Driven Atmospheric Chemistry on Rocky Habitable Zone Worlds
• Atmospheric Regimes and Trends on Exoplanets and Brown Dwarfs
• Exoplanet Clouds
• The TRAPPIST-1 Habitable Atmosphere Intercomparison (THAI). Part II: Moist Cases -- The Two Waterworlds
• The TRAPPIST-1 Habitable Atmosphere Intercomparison (THAI). Part I: Dry Cases -- The fellowship of the GCMs
• Habitability and Spectroscopic Observability of Warm M-dwarf Exoplanets Evaluated with a 3D Chemistry-Climate Model
• Simulations of Water Vapor and Clouds on Rapidly Rotating and Tidally Locked Planets: a 3D Model Intercomparison
• Origins Space Telescope Mission Concept Study Report
• THOR 2.0: Major Improvements to the Open-Source General Circulation Model
• Is ozone a reliable proxy for molecular oxygen? I. The O2-O3 relationship for Earth-like atmospheres
• Simulated Phase-dependent Spectra of Terrestrial Aquaplanets in M Dwarf Systems
• Climate Modeling of a Potential ExoVenus
• Lightning-induced chemistry on tidally-locked Earth-like exoplanets
• Sporadic Spin-Orbit Variations in Compact Multi-planet Systems and their Influence on Exoplanet Climate
• Longitudinally asymmetric stratospheric oscillation on a tidally locked exoplanet
• Wetter Stratospheres on High Obliquity Planets
• Stratospheric dayside-to-nightside circulation drives the 3-D ozone distribution on synchronously rotating rocky exoplanets
• Multiverse Predictions for Habitability: The Number of Stars and their Properties
• MIRECLE: Science Yield for a Mid-IR Explorer-Class Mission to Study Non-Transiting Rocky Planets Orbiting the Nearest M-Stars Using Planetary Infrared Excess
• The Impact of Planetary Rotation Rate on the Reflectance and Thermal Emission Spectrum of Terrestrial Exoplanets Around Sun-like Stars
• Dynamical and biological panspermia constraints within multi-planet exosystems
• Effects of transient stellar emissions on planetary climates of tidally-locked exo-earths
• Examining NHD vs QHD in the GCM THOR with non-grey radiative transfer for the hot Jupiter regime
• 3D Global climate model of an exo-Venus: a modern Venus-like atmosphere for the nearby super-Earth LP 890-9 c
• Interpolation and synthesis of sparse samples in exoplanet atmospheric modeling
• The continued importance of habitability studies
• The Mid-InfraRed Exo-planet CLimate Explorer MIRECLE: Exploring the Nearest M-Earths Through Ultra-Stable Mid-IR Transit and Phase-Curve Spectroscopy
• The effect of a biosphere on the habitable timespan of stagnant-lid planets and implications for the atmospheric spectrum
• Hydrocarbon complexity and photochemical shielding of prebiotic feedstock molecules in exoplanet atmospheres