Schematic view of radial extent and enrichment of the protosolar disk. The yellow disk indicates the extent of the hydrogen and helium gas disk which has, by definition, an enrichment of unity. The smaller dust disk is shown in red. The inner cylinders indicate possible enrichments in Ar, N₂, Kr and Xe, respectively, following the inner drift of pebbles and the release of these volatiles at their respective evaporation fronts. In this simple picture (Guillot & Hueso 2006; Bitsch & Mah 2023), the local enrichment is highest for the species with the highest condensation temperature. The capture of these volatiles in amorphous ice and their release at the location of the amorphous to crystalline ice transition (Monga & Desch 2015; Mousis et al. 2019) has also been proposed. In this case the enrichment of the gas in all the considered volatiles would start at this location and would probably be more uniform. In the figure, the dashed circle indicates the zone over which Jupiter would accrete gas. Outside of this zone, the gas should be lost by photoevaporation or disk truncation, otherwise it would eventually flow into Jupiter’s region and its accretion would dilute the atmospheric enrichment.