Simulation of Jovian moist convection with an active water and ammonia
hydrological cycle using the EPIC GCM
Abstract
Jovian moist convection has been the study of both observational and
modelling attempts for several decades. In the Pioneer and Voyager era,
plumes of volatiles were observed to erupt from the deep atmosphere
regularly, prompting the question of the strength of the internal heat
flux within Jupiter’s atmosphere. Later, Galileo observed towering
convective storms coinciding with the presence of lightning. Analysis of
cloud formation on Jupiter considering the abundances of various
condensible species revealed that the most likely source of these
convective events was the deep water cloud which contains both the high
density of volatiles and necessary convective potential to breach the
upper cloud deck. In this study, we use the Explicit Planetary
Isentropic Coordinate (EPIC) atmospheric 3-dimensional general
circulation model (GCM) to study the formation of Jovian moist
convective events, using an active cloud microphysics scheme. We focus
on the region centered on the 24° N jet where plume formation has been
observed several times. We initiate cloud formation assuming different
initial deep abundance values of both water and ammonia to test the
sensitivity on the strength of plume formation and the buildup of
convective potential energy (CAPE). We find that convective activity is
affected by the thermal properties of the environment – the jet and the
North Equatorial Belt are conducive of convection while the North North
Tropical Zone is not.