Atmospheres Of Outer Planets Research Articles

Clouds, aerosols, and photochemistry in the Jovian atmosphere

In this paper we review current ideas about the composition, horizontal and vertical distribution, and microphysical properties of clouds and aerosols in Jupiter's upper troposphere and stratosphere. We also discuss several key photochemical species, their relation to aerosol formation, and their implications for transport processes. We treat photochemistry in the context of comparative planetology and point out important similarities and differences among the outer planet atmospheres. Our approach emphasizes observational data of relevance to cloud properties, and to this end we assemble a wide assortment of ground-based and spacecraft observations. We challenge some widely held views about the distribution of clouds in the troposphere and present a rationale for alternative interpretations.

Anomalous C-12H4:C-13H4 strengths in 3 NY sub 3

The C-12:C-13 ratios in the atmospheres of the outer planets are important parameters with which to test models for isotope formation and fractionation during the early history of the solar system, yielding insight into processes occurring in the primitive solar nebula. The 3 ny sub 3 spectra of methane were obtained using the Kitt Peak Solar Fourier Transform Spectrometer and a 6 m White cell. The experimental results are summarized in a table. The strength ratios for the R-branch of 3 ny sub 3 exhibit strong anomalies, with C-13H4 lines consistently weaker than their C-12H4 counterparts. The C-12:C-13 abundance ratios for the atmospheres of Jupiter and Saturn have been redetermined using the 3 ny sub 3 line-strength ratios measured.

On probing the outer planets with the Raman effect

The feasibility of using the H2 rotational Raman spectrum to investigate the physical structure of outer planet atmospheres is examined. By selecting distinct wave bands spaced throughout the visible spectrum for observation a wide range in physical depth can be probed. On the basis of a semi‐infinite homogeneous pure H2 atmospheric model, computations of the strengths of the S(0) and S(1) lines have been made for a wide range of physical conditions. For each characteristic wavelength the ratio of the S(0)/S(1) line strengths is independent of the presence of aerosol particles. It provides a useful estimate of Boltzmann temperature. In contrast, the absolute strengths of the S(0) and S(1) lines are extremely sensitive to haze. Extremely small quantities of aerosol particles can be detected even at high altitudes. Initial applications of the Raman probe technique to Jupiter and Uranus are reported. For Jupiter a weak aerosol haze appears to exist at an H2 column density of ⪝17 km amagat. For Uranus, aerosol particles appear to be present at an H2 column density of ⪝104 km amagat. In addition, a significant temperature inversion may be present in the same region of the atmosphere.