Atmospheric modelling of tidally-locked exoplanets

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Climate models have enabled us to examine the governing processes, dynamics, and lim- its of the Earth system, including of the feedbacks that can drastically transform the climate. These models have also been adapted to study the diversity of other planetary climatologies, and in particular of the range of habitable conditions that might lead to the emergence of life. The most abundant group of potentially habitable planets are those orbiting M-dwarf stars, of which the recent launch and technological advances of the James Webb Space Telescope (JWST) will aid further investigation. Preliminary modelling studies have shown that the at- mospheres of these planets may be stable despite their tidally-locked nature, albeit with an unusual climatology which may have implications on their habitability. Making use of the plethora of Earth climate data available, the project will begin by exploring a climatologically- based definition of surface habitability. Specifically, this definition should have the ability to be applied to 3D climate model output data, as well as allow a comparison of habitability be- tween a diverse range of planets with different orbital properties and stellar hosts. This will be followed by an investigation into the 'generalisation' of surface habitability, that is, determin- ing whether the 'aquaplanet simplification' commonly used in exoplanet climate modelling studies provides an adequate approximation in representing the climate and habitability of an Earth-like planet some unknown continental configuration. The final chapter focuses upon the habitability of tidally-locked planets, aiming to connect the atmospheric dynamics with spatial patterns of surface habitability, and building upon the literature which establishes a dependence of planetary rotation period with atmospheric circulation regime.