The carbon monoxide fourth positive bands in the Venus dayglow 1. Synthetic spectra
Abstract
Spectral observations of the Venus dayglow from 1200-1800 Å were made with the Pioneer Venus ultraviolet spectrometer (13-Å resolution), a sounding rocket telescope and spectrometer (4-Å resolution, and the International Ultraviolet Explorer (0.4-Å resolution). Emissions due to HI, CI, OI, and the CO fourth positive system are identified. Emission rate factors for the fourth positive system are calculated using a high-resolution solar flux. The importance of solar emission line excitation to this fluorescence spectrum is shown. In particular, several bands of the v' = 14 progression are identified and their excitation mechanism is shown to be fluorescent scattering of solar Lyman α radiation. The CO (14,5) band at 1392 Å is a prominent unblended spectral feature in the Venus dayglow. The (14,3) and (14,4) bands at 1317 and 1354 Å are blended with the OI 1304- and 1356-Å features in lower-resolution spectra. This identification resolves the problem of the interpretation of the ratio of the OI 1304/1356 Å emissions from Venus. It also provides an additional remote sensing technique to determine the density distribution of CO in the upper atmosphere of Venus.
- Publication:
-
Journal of Geophysical Research
- Pub Date:
- October 1981
- DOI:
- 10.1029/JA086iA11p09115
- Bibcode:
- 1981JGR....86.9115D
- Keywords:
-
- Astronomical Spectroscopy;
- Carbon Monoxide;
- Dayglow;
- Pioneer Venus Spacecraft;
- Ultraviolet Spectra;
- Venus Atmosphere;
- Emission Spectra;
- Fluorescence;
- Iue;
- Line Spectra;
- Spectral Bands;
- Spectral Sensitivity