Speaker: Professor Yonggang Liu from Peking University

Title: "Influence of Continental Location and Glaciation on the Climate of a Tidally-locked Exoplanet"

Abstract: The climate on a 1:1 tidally-locked exoplanet which has a circular continent is studied with a fully coupled atmosphere-ocean general circulation model (AOGCM). It is found that the climate is sensitive to the location of the continent; it is generally warmer when the continent is in the high latitude and to the east of substellar point than when it is near the equator and to the west of substellar point. The global mean surface temperature can differ by as much as 24 °C. Moreover, when ice sheet grows on the continent, it causes re-orientation of the planet. The location of the continent thus changes, which further induces changes of the global climate. Because the re-orientation tends to move the glaciated continent towards the substellar point, the climate of a relatively slowly rotating tidally-locked exoplanet always descends towards a cold state with rare exceptions. I will show a few examples for different viscosity profiles of the planet.