Numerical modeling of Jupiter's moist convection layer

Moist convection of Jupiter's atmosphere is examined using a large-domain t wo-dimensional fluid dynamical model with simplified cloud microphysics of water. The result shows that the water condensation level acts as a dynamic al and compositional boundary. The convection below the condensation level is characterized by a steady regular cellular structure and a homogeneous d istribution of water mixing ratio. Above the condensation level, cloud elem ents accompanied by the upward motion develop and disappear irregularly but successively, and water mixing ratio is highly inhomogeneous. The horizont al average of mixing ratio decreases rapidly with height just above the con densation level, resulting in a distinctive stable layer at 5 bar. The stab le layer prevents the air masses above and below it from mixing with each o ther. As a result, the upper dry air does not reach 20 bar level, where the Galileo probe observed low humidity.