Accurate jovian radio flux density measurements show ammonia to be subsaturated in the upper troposphere

The availability of new accurate radio flux densities of Jupiter in and around the λ ≃ 1.3   cm ammonia absorption band, one from ground-based radio data and five from the WMAP satellite, permits re-examination of the structure of the jovian upper troposphere. These flux densities, with accuracies of 1–3%, indicate that the jovian atmospheric ammonia is globally subsaturated within and above the ammonia cloud tops, 0.4   bar ⩽ P ⩽ 0.6   bar , and subsolar (by a factor of 2) below the cloud base, 0.6   bar ⩽ P ⩽ 2   bar .