Solar heating and internal heat flow on Jupiter

Abstract

Models of convection in Jupiter's interior are studied to test the hypothesis that internal heat balances the absorbed sunlight at each latitude. Such a balance requires that the ratio of total emitted heat to absorbed sunlight be above a critical value 4/π ≈ 1.27. The necessary horizontal heat transport then takes place in the interior instead of in the atmosphere. Regions of stable stratification can arise in the interior owing to the effects of solar heating and rotation. In such regions, upward heat transfer takes place on sloping surfaces, as in the Earth's atmosphere, provided there are horizontal temperature gradients. Potential temperature gradients are found to be small, and the time constant for the pattern to reach equilibrium is found to be short compared to the age of the solar system. It is suggested that Jupiter and Saturn owe their axisymmetric appearance to internal heat flow, which eliminates differential heating in the atmosphere that would otherwise drive meridional motions.