SLS – Santiago Benevides (MIT; pre-defense)

Effective drag in rotating, poorly electrically-conducting exoplanet atmospheres

The atmospheric dynamics of hot Jupiters has been the subject of many theoretical and numerical studies ever since atmospheric signatures from these planets have been observed. These exoplanet atmospheres are distinct from the familiar ones we study in our solar system in two ways: they are subject to moderate rotation and are ionized, yet poorly conducting. Early attempts at describing their dynamics depended on a parametrization of the magnetic effects which represented the Lorentz force as a drag-like term in the momentum equation, dubbed “MHD drag”. In this presentation, we review the origins of this approach and examine the validity of MHD drag under various magnetic parameter regimes using a series of idealized turbulence simulations subject to moderate rotation rates.