Results 251 to 260 of about 2,078,180 (298)

Investigation of sodium in the upper atmosphere

Journal of Geophysical Research: Oceans, 1980
Upper atmospheric atomic sodium abundances have been measured near Ankara (39.9°N, 32.6°E), Turkey, from February 1976 to April 1977. The daytime absorption measurements were made with a Pepsios spectrometer using the solar radiation near the D2 line of sodium at 5890 Å. Seasonal and daily variations of the sodium abundance were examined.
YEGINGIL, I, OGELMAN, H, KIZILOGLU, N
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The Upper Atmosphere

Physics Bulletin, 1958
By H. S. W. Massey and R. L. F. Boyd London : Hutchinson and Co. Ltd. Pp. xii + 333. Price 63s. The authors give an account of the present state of knowledge of the upper atmosphere the region extending from an altitude of about ten miles to some hundreds of miles into space.
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Super-rotation of Upper Atmosphere

Nature, 1971
RECENT publications1,2 report that the mean rotational speed of the Earth's upper atmosphere at altitudes of about 200–400 km is faster than that of the Earth. Rishbeth3 has suggested that an induced electric polarization field at low latitudes plays a part in this “super-rotation”. We offer here an alternative explanation, based on the Scott effect4.
D H, Weinstein, J, Keeney
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Turbulence of the upper atmosphere and isoplanatism

Applied Optics, 1979
We report the results of 1,049 measurements of the vertical profile of optical turbulence as recorded by a scintillometer above a site at White Sands Missile Range. The distributional law for these measurements is shown to be approximately log normal and examples of monthly to hourly variations in profile structure are presented.
G C, Loos, C B, Hogge
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Upper Atmosphere and Ionosphere of Mars

Science, 1966
It is argued that the single-layer ionosphere at 125 kilometers discovered in the Mariner IV occultation experiment is an F1 region coinciding with the ultraviolet photoionization peak. The CO 2 density there must be of the order of 10 11 molecules per cubic centimeter.
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Some Phenomena of the Upper Atmosphere

Proceedings of the Physical Society. Section B, 1951
The height distribution of the atmosphere depends on the temperature and the mean molecular weight of the air; recent progress in our knowledge of these two quantities will be reviewed, the main sources of information being outlined. The motions (winds and tides) in the upper atmosphere will similarly be considered. The main gross uncertainty regarding
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On the Semiannual Variation of the Upper Atmosphere

Planetary and Space Science, 1970
The effects of the seasonal variations of the dynamical properties of the lower thermosphere at and below 120 km, such as the dissociation of the molecular oxygen, the turbopause levels of different constituents and the temperature on the semiannual variation (SAV) in the upper atmosphere, have been studied on the basis of the steady state models.
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The Upper Atmosphere

Journal of the American Medical Association, 1959
H. S. W. MASSEY, R. L. F. BOYD
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Radar Measurement of the Upper Atmosphere

Science, 1979
In the last two decades large radars have proved to be powerful instruments for the measurement of the properties of the upper atmosphere. These radars were used initially to measure properties of the ionosphere by the Thomson scattering technique at heights above 100 kilometers.
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Rotation of the Variation of Upper Atmosphere

Nature, 1971
FROM observations of satellite orbits it has been deduced that the atmosphere above about 200 km altitude rotates 20–30% faster than the Earth, so that there exists a net west-to-east wind of order 100 m s−1 (refs. 1, 2). This “super-rotation” has not yet been satisfactorily explained.
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