MEGA-MIP: M-Earth Global Atmospheres Model Intercomparison Project

M-dwarf stars are smaller and cooler than solar-type stars, yet are the most abundant and long-lived in the Galaxy. They are also more likely to host rocky planets, particularly within the circumstellar Habitable Zone, with the caveat that these planets are likely to be tidally-locked to their host star with one hemisphere permanently illuminated and the other in perpetual darkness. Modelling studies have so far shown that these atmospheres may be protected against collapse on the nightside given sufficient pressure, as well as identifying multiple atmospheric circulation regimes which are determined primarily by planetary rotation rate. Whilst the majority of studies examine simulations from a single model, the use of multimodel intercomparisons (e.g., CUISINES) is becoming increasingly popular, with results suggesting some diversity in simulated atmospheres and climate. Furthermore, with the characterisation of temperate rocky exoplanet atmospheres on the horizon for observers, the resultant ensemble spread may help to constrain uncertainties and degeneracies within future observations. MEGA-MIP aims to build upon the work of predecessors such as THAI and Haqq-Misra et al. (2018), using an ensemble of 3D general circulation models adapted for use in exoplanet climatology to simulate a set of tidally-locked terrestrial planets along the inner edge of the Habitable Zone. Particular emphasis will be placed upon discussing the preliminary results from the intercomparison, which examine the diversity of the global atmospheric circulation, surface climate, and habitability across the distinct circulation regimes introduced by Haqq-Misra et al. (2018).