The morphology of Titan's methane bands. I - Comparison with a reflecting layer model

Abstract

view Abstract Citations (23) References (20) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The morphology of Titan's methane bands. I. Comparison with a reflecting layer model. Trafton, L. Abstract Titan's spectrum at moderate resolution is compared with and contrasted to Saturn's spectrum from 5800 to 12,000 A. The filling-in of Titan's bands arises partly from a curve-of-growth effect caused by the different pressures and visible-methane abundances in the two atmospheres. Most of Titan's bands are saturated in the sense that the absorption of both their stronger and weaker lines is affected by the pressure. On the other hand, the weaker lines of Saturn's bands lie essentially on the linear part of the curve of growth. In principle, this permits us to evaluate the parameters of a band model describing the mean transmission versus wavelength for a given band by using the spectra of both planets simultaneously. We find, however, that the reflecting layer model cannot be reconciled with the observations of Titan. This is true whether or not results from an analysis of the R(5) manifold of Titan's 3v3 methane band are considered. This implies that aerosol scattering plays a significant role in Titan's band formation. The most likely candidate for such an aerosol is frozen methane particles. Subject headings: abundances, planetary - line formation - Saturn - satellites - spectra, planetary Publication: The Astrophysical Journal Pub Date: February 1975 DOI: 10.1086/153385 Bibcode: 1975ApJ...195..805T Keywords: Astronomical Models; Methane; Planetary Atmospheres; Saturn (Planet); Spectral Bands; Titan; Absorption Spectra; Aerosols; Atmospheric Models; Atmospheric Stratification; Infrared Astronomy; Light Scattering; Molecular Spectra; Optical Reflection; Spectral Line Width; Lunar and Planetary Exploration full text sources ADS |