The Abundance of Hydrogen in the Atmosphere of Jupiter

New observations of the hydrogen quadrupole absorptions in the spectrum of Jupiter are presented. With the help of a recently published curve of growth and new calculations of the line strengths, it is possible to derive the corresponding atmospheric abundance of hydrogen. The result is based on the observation of two lines that give nearly identical values: 85 km amagat for 3-0 S(1); 90 km amagat for 4-0 S(1). These results appear to be consistent with our observations of other lines in the quadrupole bands, and it is demonstrated that they are compatible with other determinations of the hydrogen abundance. A comparison of methane and hydrogen abundances suggests that the relative abundances of the elements in the Jovian atmosphere are similar to, if not identical with, solar values This suggestion is consistent with observed line half-widths. Multiple scattering may be invoked to explain a number of observations, but it is evident that variations in the gross structure of the clouds with position on the observable hemisphere must also play a significant role in determining the optical behavior of the Jovian atmospher