摘要：The inflated radii of giant short-period extrasolar planets collectively indicate that the interiors of hot Jupiters are heated by someanomalous energy dissipation mechanism. Although a variety of physical processes have been proposed to explain this heating, recentstatistical evidence points to the confirmation of explicit predictions of the Ohmic dissipation theory, elevating this mechanism as themost promising candidate for resolving the radius inflation problem. In this work, we present an analytic model for the dissipation rateand derive a simple scaling law that links the magnitude of energy dissipation to the thickness of the atmospheric weather layer. Fromthis relation, we find that the penetration depth influences the Ohmic dissipation rate by an order of magnitude. We further investigatethe weather layer depth of hot Jupiters from the extent of their inflation and show that, depending on the magnetic field strength, hotJupiter radii can be maintained even if the circulation layer is relatively shallow. Additionally, we explore the evolution of zonal windvelocities with equilibrium temperature by matching our analytic model to statistically expected dissipation rates. From this analysis,we deduce that the wind speed scales approximately as 1/p Teq − T0, where T0 is a constant that equals T0 ∼ 1000 K − 1800 Kdepending on planet-specific parameters (radius, mass, etc.). This work outlines inter-related constraints on the atmospheric flow andthe magnetic field of hot Jupiters and provides a foundation for future work on the Ohmic heating mechanism.
关键词：magnetohydrodynamics (MHD);planets and satellites: atmospheres;planets and satellites: magnetic fields;planets and satellites: interiors;planets and satellites: gaseous planets
