Can Shallow Jets be Stable in Jovian Atmosphere?
Spacecraft observations of Jupiter revealed multiple atmospheric jets alternately blowing eastward and westward at the cloud level. Subsequent observations have shown that those zonal jets are remarkably stable both in time and space. Temperature measurements above the clouds suggest that the jets become slower with height at those altitudes. Much less is known about the winds and temperatures below the clouds. Direct measurements of the atmosphere below the thick clouds are extremely difficult on Jupiter. The only in situ measurement to date, the Galileo probe experiment, showed that the wind speed increases with depth from the 1-5 bar-level and then stays almost constant until at least 22 bar; however, this condition may be representative only of the probe entry site. The large-scale structure of the zonal jets and temperature below the clouds remain a major unknown in Jupiter’s atmosphere. Theoretical studies use various hydrodynamic stability theorems to test whether a particular d