Radiation Balance of Jupiter and Saturn

Abstract

IT is frequently stated^1,2 that the radiation balance of Jupiter presents a significant problem in that the temperature derived for the cloud tops (∼165° K) is considerably higher than the value which would be achieved by a rapidly rotating body having Jupiter's characteristics in simple equilibrium with solar radiation (∼125° K). This discrepancy has been cited as possible evidence for thermal radiation from the interior of the planet; that is, it has been suggested that Jupiter might still be cooling down from an early, high-temperature phase². The role of the atmosphere in maintaining the thermal balance has generally been disregarded since it has been assumed that the known constituents were all transparent in the wavelength region of importance (20–40µ). The situation for Saturn is very similar; the temperatures are simply somewhat lower. A number of recent findings when considered together appear to require a revision of these ideas.