Abstract
DIRECT simultaneous measures of temperature and pressure up to 25 kilometres, by sounding balloons, give complete information as to the variation of pressure, density, and temperature over this range. The temperature falls in the first 10 kilometres from 285° absolute to 220°, and then remains constant up to 25 or 30 kilometres. The temperature above this height was a subject merely for speculation until Lindemann and Dobson published their theory and discussion of meteors. They concluded that the temperature remains at 220° up to 50 or 60 kilometres, after which it rises (perhaps rather rapidly) to about 300°, which is its value up to about 140 kilometres; thus at this height the air is warmer than near the ground. This rise of temperature is inferred from the estimated densities of the air between 60 and 150 kilometres, the density at 100 km. being more than ten times as great as it would be if the temperature had remained at 220°. Higher up the difference between the estimated density and that calculated on the latter assumption is still greater. The mean free molecular path, calculated on the assumption that the air is mainly nitrogen over this range, increases from about 1 cm. at 90 km. to about 10 cm. at 130 km.
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CHAPMAN, S. The Electrical State of the Upper Atmosphere1. Nature 117, 454 (1926). https://doi.org/10.1038/117454a0
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DOI: https://doi.org/10.1038/117454a0