Ammonia-water solution cloud modeling of gas giant planets via phase equilibrium calculations

Gas giant planet atmospheres are composed primarily of hydrogen and helium along with trace constituents including methane, ammonia, water vapor, hydrogen sulfide, phosphine and others. Since the seminal work of Lewis (1969), many researchers have used 1-D adiabatic atmospheric models to calculate solid and liquid cloud structures in the giant planets. In this contribution, traditional cloud modeling approaches for liquid clouds are reconsidered with respect to state-of-the-art techniques derived from fundamental principles governing the vapor-liquid equilibrium (VLE) conditions. The technique is discussed from the perspective of binary mixtures with the provision that it can be generalized for multi-component mixtures. As a purposeful illustration, up-to-date thermodynamic properties of water and ammonia mixtures are used to investigate the aqueous ammonia clouds on Jupiter. Comparisons with the traditional approach are presented, as methodologies applied in constructing Jupiter's atmosphere. This work is related to the Microwave Radiometer (MWR) Experiment on the Juno spacecraft, which has the capability of sensing the brightness temperature of Jupiter in the vicinity of the cloud structures, from 0.5 atm to over 300 atm pressure.