15 October: Maria di Paolo

Speaker: Maria di Paolo (University of East Anglia)

Date: Wednesday 15 October 2025

Time: 15:00

Location: Physics 3.21

Climate Patterns of Spin-Orbit Resonant Exoplanets Around Low-Mass Stars

M dwarfs are the most promising candidates for finding habitable worlds through atmospheric characterization. Planets in the habitable zone of low-mass stars experience intense tidal forcings and often become tidally locked. Despite the majority of research being centered on the climate dynamics of synchronously rotating planets in this scenario, synchronous rotation is not an inevitable outcome of tidal locking. Several different circumstances can result in an asynchronous rotation, and in some instances can lead to spin-orbit resonances (SORs).

In this talk, we will explore the climates of two different 3:2 SOR scenarios with a coupled atmosphere-ocean general circulation model. Given the crucial role played by the oceans in shaping planetary climate, we adopt two different ocean tidal forcing parameterizations for each SOR scenario. Each of these cases are simulated with both a dynamical ocean and a thermodynamical ocean.

Our findings reveal striking differences between the analyzed resonant cases and the commonly studied synchronous cases. Periodic climate patterns are observed, with climatic features such as clouds and rainfall exhibiting a 60° longitudinal shift relative to the substellar point. The evolution of quantities such as the planetary thermal emission during a stellar period is potentially noteworthy from the observational point of view.