Connecting the dots III: Night side cooling and surface friction affect climates of tidally locked terrestrial planets

Abstract

We investigate how night side cooling and surface friction impact surface temperatures and large scale circulation for tidally locked Earth-like planets. For each scenario, we vary the orbital period between $P_{rot}=1-100$~days and capture changes in climate states. We find drastic changes in climate states for different surface friction scenarios. For very efficient surface friction ($t_{s,fric}=$ 0.1 days), the simulations for short rotation periods ($P_{rot}\le$ 10 days) show predominantly standing extra tropical Rossby waves. These waves lead to climate states with two high latitude westerly jets and unperturbed meridional direct circulation. In most other scenarios, simulations with short rotation periods exhibit instead dominance by standing tropical Rossby waves. Such climate states have a single equatorial westerly jet, which disrupts direct circulation. Experiments with weak surface friction ($t_{s,fric}=10-100$ days) show decoupling between surface temperatures and circulation, which leads to strong cooling of the night side. The experiment with $t_{s,fric}=100$ days assumes climate states with easterly flow (retrograde rotation) for medium and slow planetary rotations $P_{rot}=12-100$~days. We show that an increase of night side cooling efficiency by one order of magnitude compared to the nominal model leads to a cooling of the night side surface temperatures by 80-100~K. The day side surface temperatures only drop by 25~K at the same time. The increase in thermal forcing suppresses the formation of extra tropical Rossby waves on small planets ($R_P=1R_{Earth}$) in the short rotation period regime ($P_{rot}\le$ 10 days).

arXiv comment25 pages, 21 figures, accepted by MNRAS

References in corpus (16)

• A super-Earth transiting a nearby low-mass star
• Equatorial superrotation on tidally locked exoplanets
• Stabilizing Cloud Feedback Dramatically Expands the Habitable Zone of Tidally Locked Planets
• Transits of Earth-Like Planets
• Strong Dependence of the Inner Edge of the Habitable Zone on Planetary Rotation Rate
• 3D climate modeling of close-in land planets: Circulation patterns, climate moist bistability and habitability
• Asynchronous rotation of Earth-mass planets in the habitable zone of lower-mass stars
• The Atmospheric Circulation of the Hot Jupiter WASP-43b: Comparing Three-Dimensional Models to Spectrophotometric Data
• Towards the Minimum Inner Edge Distance of the Habitable Zone
• Connecting the dots II: Phase changes in the climate dynamics of tidally locked terrestrial exoplanets
• Gliese 581g as a scaled-up version of Earth: atmospheric circulation simulations
• The atmospheric circulation of the super Earth GJ 1214b: Dependence on composition and metallicity
• Atmospheric Circulation and Composition of GJ1214b
• Connecting the dots: A versatile model for the atmospheres of tidally locked Super-Earths
• On the equilibrium rotation of Earth-like extra-solar planets
• Optimal Measures for Characterizing Water-rich Super-Earths

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