<P> The deep model was first proposed by Busse in 1976 . His model was based on another well - known feature of fluid mechanics, the Taylor--Proudman theorem . It holds that in any fast - rotating barotropic ideal liquid, the flows are organized in a series of cylinders parallel to the rotational axis . The conditions of the theorem are probably met in the fluid Jovian interior . Therefore, the planet's molecular hydrogen mantle may be divided into cylinders, each cylinder having a circulation independent of the others . Those latitudes where the cylinders' outer and inner boundaries intersect with the visible surface of the planet correspond to the jets; the cylinders themselves are observed as zones and belts . </P> <P> The deep model easily explains the strong prograde jet observed at the equator of Jupiter; the jets it produces are stable and do not obey the 2D stability criterion . However it has major difficulties; it produces a very small number of broad jets, and realistic simulations of 3D flows are not possible as of 2008, meaning that the simplified models used to justify deep circulation may fail to catch important aspects of the fluid dynamics within Jupiter . One model published in 2004 successfully reproduced the Jovian band - jet structure . It assumed that the molecular hydrogen mantle is thinner than in all other models; occupying only the outer 10% of Jupiter's radius . In standard models of the Jovian interior, the mantle comprises the outer 20--30% . The driving of deep circulation is another problem . The deep flows can be caused both by shallow forces (moist convection, for instance) or by deep planet - wide convection that transports heat out of the Jovian interior . Which of these mechanisms is more important is not clear yet . </P> <P> As has been known since 1966, Jupiter radiates much more heat than it receives from the Sun . It is estimated that the ratio between the power emitted by the planet and that absorbed from the Sun is 1.67 ± 0.09 . The internal heat flux from Jupiter is 5.44 ± 0.43 W / m, whereas the total emitted power is 335 ± 26 petawatts . The latter value is approximately equal to one billionth of the total power radiated by the Sun . This excess heat is mainly the primordial heat from the early phases of Jupiter's formation, but may result in part from the precipitation of helium into the core . </P> <P> The internal heat may be important for the dynamics of the Jovian atmosphere . While Jupiter has a small obliquity of about 3 °, and its poles receive much less solar radiation than its equator, the tropospheric temperatures do not change appreciably from the equator to poles . One explanation is that Jupiter's convective interior acts like a thermostat, releasing more heat near the poles than in the equatorial region . This leads to a uniform temperature in the troposphere . While heat is transported from the equator to the poles mainly via the atmosphere on Earth, on Jupiter deep convection equilibrates heat . The convection in the Jovian interior is thought to be driven mainly by the internal heat . </P>

Main gases in the atmosphere of jupiter and saturn