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Science 17 December 1976:
Vol. 194. no. 4271, pp. 1295 - 1298
DOI: 10.1126/science.194.4271.1295
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Articles

Composition and Structure of the Martian Upper Atmosphere: Analysis of Results from Viking

M. B. MCELROY 1, T. Y. KONG 1, Y. L. YUNG 1, and A. O. NIER 2

1 Center for Earth and Planetary Physics, Harvard University, Cambridge, Massachusetts 02138
2 School of Physics and Astronomy, University of Minnesota, Minneapolis 55455

Densities for carbon dioxide measured by the upper atmospheric mass spectrometers on Viking 1 and Viking 2 are analyzed to yield height profiles for the temperature of the martian atmosphere between 120 and 200 kilometers. Densities for nitrogen and argon are used to derive vertical profiles for the eddy diffusion coefficient over the same height range. The upper atmosphere of Mars is surprisingly cold with average temperatures for both Viking 1 and Viking 2 of less than 200°K, and there is significant vertical structure. Model calculations are presented and shown to be in good agreement with measured concentrations of carbon monoxide, oxygen, and nitric oxide.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Atomic Hydrogen on Mars: Measurements at Solar Minimum.
J. S. LEVINE, D. S. MCDOUGAL, D. E. ANDERSON JR., and E. S. BARKER (1978)
Science 200, 1048-1051
   Abstract »    PDF »
Scientific Results of the Viking Missions.
G. A. Soffen and G. A. SOFFEN (1976)
Science 194, 1274-1276
   Abstract »    PDF »
Structure of the Neutral Upper Atmosphere of Mars: Results from Viking 1 and Viking 2.
A. O. Nier, A. O. NIER, and M. B. MCELROY (1976)
Science 194, 1298-1300
   Abstract »    PDF »


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Science. ISSN 0036-8075 (print), 1095-9203 (online)