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Diurnal variations in thermospheric hydrogen
Author(s) -
Patterson T. N. L.
Publication year - 1970
Publication title -
reviews of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.087
H-Index - 156
eISSN - 1944-9208
pISSN - 8755-1209
DOI - 10.1029/rg008i002p00461
Subject(s) - exosphere , thermosphere , hydrogen , atmospheric sciences , asymmetry , atmosphere (unit) , altitude (triangle) , environmental science , diurnal temperature variation , physics , astrobiology , ionosphere , meteorology , geophysics , ion , geometry , mathematics , quantum mechanics
The escape of atomic hydrogen from the high regions of the earth's atmosphere plays a fundamental role in determining the altitude distribution of this gas. The rate of escape is well known to be a very sensitive function of temperature, with the result that, if hydrogen gas responded instantaneously to diurnal exospheric temperature variations, a day‐night asymmetry as high as 20 in the concentration of hydrogen might be expected. Studies during the last few years have shown, however, that lateral flow of hydrogen gas in the exosphere will cause a considerable reduction in the magnitude of this asymmetry, a ratio of the order of 2 being much more likely. In this paper the results of earlier work will be reviewed and updated by more recent studies.