Seminar by Clàudia Soriano Guerrero, CSIC, Barcelona
We present simulation of induction equations in the atmosphere of Hot Jupiters (HJ). These giant planets have inflated radii that cannot be accounted for standard cooling models for planetary evolution. Various possible mechanisms have been proposed, among which is Ohmic dissipation of currents. In order to quantify the such dissipation, we study the combined effect of winding and atmospheric turbulence in box simulations representing narrow day-side atmospheric columns. We used realistic profiles for the wind velocity and pressure, obtained from GCM simulations, for different exoplanets. By including the corresponding resistivity, we evaluate the amplifications of the atmospheric magnetic field, and study the effects of enforcing turbulent perturbations in addition to the zonal wind in the upper atmosphere. Very high values for magnetic fields, up to kG for the hottest planets and be reached locally around the shear layer. The simulations performed in this study suggest show that the strong electrical currents generated might locally be enough to explain the inflated radii of Hot Jupiters, if they penetrate inner layers of the planet and an important variability of the induced currents depending on the temperature of local temperature of the planet. We briefly discuss the implication for the radio detectability.
Host: Chengcheng Xin