Upper limits to trace constituents in Jupiter's atmosphere from an analysis of its 5-μm spectrum

A high-resolution (0.6 cm^-1) spectrum of Jupiter at 5 μm recorded at the Kuiper Airborne Observatory is used to determine upper limits to the column density of 19 molecules. The upper limits to the mixing ratios of SiH₄, H₂S, HCN, and simple hydrocarbons are discussed with respect to current models of Jupiter's atmosphere. These upper limits are compared to expectations based upon the solar abundance of the elements. This analysis permits upper limit measurements (SiH₄), or actual detections (GeH₄), of molecules with mixing ratios with hydrogen as low as 10^-9. In future observations at 5 μm the sensitivity of remote spectroscopic analyses should permit the study of constituents with mixing ratios as low as 10^-10, which would include the hydrides of such elements as Sn and As as well as numerous organic molecules.