The Temperature and Ammonia Profiles in the Jovian Atmospheres from Inversion of the Jovian Emission Spectrum

Abstract

Inversion techniques developed for remote soundings of the Earth's atmosphere by meteorological satellites are applied to the few earth-based observations of the Jovian emission spectrum. With a minimum of assumptions, it is possible to obtain directly from the observed spectra the profiles of atmospheric temperature and ammonia abundance. The temperature profile is obtained from inversion of the radiances observed in the infrared bands of methane and hydrogen. With the use of the derived temperature profile, the ammonia abundance profile is obtained from radiances observed in the infrared and microwave absorption bands of ammonia. The temperature profile is characterized by a definite tropopause region with a temperature of about 11 v K and by a stratospheric region in which the temperature slowly increases with altitude. The derived ammonia profile indicates the presence of a saturated ammonia layer with a base temperature of 140 K. It is concluded that inversion of infrared and microwave emission spectra provides a powerful technique for sounding the Jovian atmosphere, and that more accurate measurements should be obtained from fly-bys and earth-based observations. Subject headings: abundances, planetary - atmospheres, planetary - Jupiter