Thermodynamics of atmospheric circulation on hot Jupiters

TL;DR

This paper explores the thermodynamics of atmospheric circulation on hot Jupiters, emphasizing the importance of energy dissipation mechanisms and the limitations of certain simulation models that neglect energy conservation.

Contribution

It highlights the need for explicit energy dissipation and recovery processes in models to accurately simulate atmospheric dynamics on hot Jupiters.

Findings

Simulations often violate energy conservation without explicit dissipation.

Neglecting physical drag sources can overestimate wind speeds.

Effective heat redistribution is crucial for steady-state circulation.

Abstract

Atmospheric circulation on tidally-locked exoplanets is driven by the absorption and reradiation of heat from the host star. They are natural heat engines, converting heat into mechanical energy. A steady state is possible only if there is a mechanism to dissipate mechanical energy, or if the redistribution of heat is so effective that the Carnot efficiency is driven to zero. Simulations based on primitive, equivalent-barotropic, or shallow-water equations without explicit provision for dissipation of kinetic energy and for recovery of that energy as heat, violate energy conservation. More seriously perhaps, neglect of physical sources of drag may overestimate wind speeds and rates of advection of heat from the day to the night side.