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Young, L. G.

Publications and source records attributed to Young, L. G..

9 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Transmission of CO2 in the atmosphere of Venus for the spectral region near 7 microns

The transmission in the 7-micron 'window' of Venus was calculated for a 7-layer model atmosphere. The synthetic spectra show that radiation from the layer 20-30 km above the surface would reach the top of the atmosphere between 6.2 and 7.0 microns if there were no absorption besides the isotopic CO2 bands; for the 7.0- to 8.2-micron region, the radiating level would be located 40-50 km above the surface of Venus. The brightness temperature for the entire region is 430 K; for the above two regions it is 494 and 341 K, respectively.

Young, L. G.↗
NASA NTRS1974

Spectroscopic observations of spatial and temporal variations on Venus

Details of the Table Mountain spectroscopic patrol of Venus in September-October 1972 are given. The data indicate systematic variation over the disc, with more CO2 absorption near the terminator than at the limb, and slightly more in the southern than in the northern hemisphere. The semiregular four-day variation, reported to occur simultaneously over the disk at 8689 A by Young et al. (1973), is confirmed by observations of the 7820 A and 7883 A CO2 bands.

Young, A. T.↗
NASA NTRS1974

Infrared spectra of Venus

A historical account of observations of Venus and their interpretation is given. The major constituent of the atmosphere on Venus (CO2) was detected spectroscopically forty years ago, and minor constituents (CO, HF, HCl) have been found more recently. The infrared spectra also provide a means of studying the motions of her cloudly atmosphere. The composition of the clouds has been sought in the reflection spectrum of Venus, and some of the evidence for their nature is discussed.

Young, L. G.↗
NASA NTRS1973

The planet Venus - A new periodic spectrum variable.

The apparent strength of CO2 absorptions in the spectrum of Venus varies by 20% in a period of 4 days. The variations are synchronous over the disk, and thus represent a fundamental dynamical mode of the atmosphere.

Young, L. G.↗
NASA NTRS1972

Observing Venus near the sun.

Discussion of the special requirements posed by telescopic observing near the sun. The sky brightness in the image plane must be kept to a minimum. Sunlight scattered from dust in the atmosphere or on the optical surfaces is the main difficulty, particularly at red and infrared wavelengths where Rayleigh scattering by air molecules is weak. Atmospheric dust is less troublesome at high altitudes and in dry climates than at low, humid sites. Excellent seeing is required, especially to get the thin crescent of Venus at inferior conjunction into the narrow slit of a spectrograph. The spectroscopic phase effect of Venus is discussed, and the procedures used to carry out observations near the sun are described in detail.

Young, A. T.↗