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Schorn, R. A. J.

Publications and source records attributed to Schorn, R. A. J..

High dispersion spectroscopic observations of Venus near superior conjunction. IV - Results for the carbon dioxide bands in the IV-N photographic region

Phase curves for the CO2 bands at 7883, 7820, and 8689 A are presented. While the weaker bands at 7820 and 7883 A show a definite 'inverse phase effect,' the band at 8689 A shows a more normal phase curve; it also exhibited much larger day-to-day variations in the CO2 abundance near superior conjunction in 1971. Because the variation of the phase curves with band strength is comparable to temporal variations on Venus, simultaneous observations of strong and weak bands are still needed to determine the dependence on band strength accurately.

Young, L. D. G.↗

High-dispersion spectroscopic observations of Venus near superior conjunction. I - The carbon dioxide band at 7820 A

Nine plates of the 7820-A CO2 band were taken in 1971. A curve-of-growth analysis of the CO2 lines indicates a rotational temperature of 241 + or - 2 K, with an average slope to the curve of growth of 0.60 + or - 0.03. The Venus phase angle ranged from 7.2 to 10.7 deg. The equivalent widths of the 1971 data fall on a smooth curve fit through the 1969 data for this band; there does not appear to be any discontinuity in the phase curve at small phase angles.

Young, L. D. G.↗

High-dispersion spectroscopic observations of Venus during 1968 and 1969. II - The carbon-dioxide band at 8689 A

Results are reported for an extensive series of high-resolution spectroscopic observations of the CO2 band at 8689 A in the atmosphere of Venus which were made over a period of one year at a dispersion of 2 A/mm for Venus phase angles varying from 10 to 126 deg. The equivalent widths of lines in the band are measured, the rotational temperature is calculated, and the CO2 abundance over various areas on the planet is determined. The results are compared with those of previous observations of the CO2 bands at 8689, 7820, and 7883 A, and good agreement is found regarding the temperatures and abundances derived for the different bands. It is concluded that the CO2 abundance varies over the planet and that its distribution does not remain constant with time.

Schorn, R. A. J.↗

High-dispersion spectroscopic observations of Venus during 1968 and 1969 II. The carbon-dioxide band at 8689A

Thirty well-exposed photographic plates showing the spectrum of the carbon dioxide band at 8689A in the atmosphere of Venus were obtained during 1968 and 1969. All spectra were obtained at a dispersion of 2 A/mm for Venus phase angles varying from 10 deg. to 126 deg. Rotational temperatures ranging from 236 K to 274 K were found. The average value of the rotational temperature is 246 + or - 1 K (one standard deviation); for 1967 observations, the rotational temperatures ranged from 222 to 248 K, with an average value of 238 + or - 4 K. The variation of the equivalent width of the 8689A band, with Venus phase angle, was very similar for the two sets of observations (53 plates). The temporal variations, of approximately 30 percent, were comparable with the phase variations over this limited range of phase angle.

Schorn, R. A. J.↗

High dispersion spectroscopic studies of Mars. V - A search for oxygen in the atmosphere of Mars.

In order to set a new upper limit on the amount of diatomic oxygen in the atmosphere of Mars, we have reduced a number of high-dispersion spectra of the 7620 A band of oxygen obtained during the 1969 apparition of Mars. Our new upper limit is 15 atm cm(stp) for the Martian abundance in a single vertical path. This result confirms and lowers the 1963 upper limit of 70 cm atm(stp) by Kaplan, Muench, and Spinrad (1964). The features reported by Hunten and Belton (1966) do not appear on our spectra. Further, we have measured the pressure shift of the A band in the laboratory, and found that the shift required by their tentative identification of diatomic oxygen in the Martian atmosphere does not exist. We conclude that their tentative identification was spurious, and their upper limit dubious.

Margolis, J. S.↗