Validity of Earth-tuned convection parameterizations for tidally locked exoplanets

Assess whether the convection parameterizations used in global climate models, which are generally tuned to Earth’s atmospheric circulation, accurately represent the strong substellar convection that dominates the atmospheric dynamics of tidally locked rocky exoplanets.

Background

The study uses the intermediate-complexity PLASIM-LSG climate model to simulate tidally locked rocky exoplanets. The authors note that global climate models rely on hydrostatic primitive equations and parameterized physical processes, including convection, with parameterizations generally calibrated against Earth’s atmospheric circulation.

Tidally locked exoplanets may operate in a substantially different dynamical regime, characterized by intense convection near the permanent substellar point. Determining whether conventional Earth-calibrated convection schemes remain reliable in this setting is important for improving the fidelity of simulated temperature distributions, clouds, precipitation, and habitability estimates.

References

However, tidally locked worlds operate within a fundamentally different physical regime, as their atmospheric dynamics are usually dominated by strong convection at the substellar point. This aspect remains an open question that deserves further study.

— Assessing the Climate and Habitability of Tidally Locked Rocky Exoplanets  (2608.25451 - Bisesi et al., 26 Aug 2026) in Section 5.1, Framework novelty and climatic regime classification