The carbon-monoxide fourth positive bands in the Venus dayglow
Abstract
Spectral observations of the Venus dayglow between 1200 and 1800 A are presented. They were carried out with the Pioneer Venus orbiter ultraviolet spectrometer, a rocketborne telescope and spectrometer and the International Ultraviolet Explorer satellite. The carbon monoxide fourth positive molecular bands are identified in these spectra. Emission rate factors for the fourth positive system are calculated using a high resolution solar flux and the importance of solar emission line excitation to this fluorescence spectrum is shown. The fourth positive band emissions are analyzed and the dominant excitation mechanism is shown to be resonant and fluorescent scattering. The excitation mechanism of the (14,v") bands is shown to be fluorescent scattering of solar Lyman alpha radiation. This identification resolves the problem of the interpretation of the ratio of the OI1304/1356 A emissions from Venus. The unique character of the Lyman-alpha induced v' = 14 fluorescence spectrum is used to measure the CO density below the turbopause. It is shown not to be uniformly mixed in the region from 130 to 115 km.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1980
- Bibcode:
- 1980PhDT.........8D
- Keywords:
-
- Carbon Monoxide;
- Dayglow;
- Emission Spectra;
- Spectral Bands;
- Ultraviolet Spectra;
- Venus Atmosphere;
- Fluorescence;
- Iue;
- Lyman Alpha Radiation;
- Pioneer Venus 1 Spacecraft;
- Resonance Scattering;
- Satellite Observation;
- Solar Radiation;
- Lunar and Planetary Exploration