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Simultaneous measurements of the hydrogen airglow emissions of Lyman alpha, Lyman beta, and Balmer alpha.Comparison of Lyman-alpha, 740- to 1050-A, and Balmer-alpha airglow measurements made at 134 deg solar-zenith angle on Oct. 13, 1969, with resonance-scattering models of solar radiation. Model comparison with Lyman-alpha data fixes the hydrogen column abundance over 215 km to 2 x 10 to the 13th per cu cm within a factor of 2. Differences between the Lyman-alpha model and data indicate a polar-equatorial departure from spherical symmetry in the hydrogen distribution. A Lyman-beta model based on the hydrogen distribution found to fit the Lyman-alpha data fits the spatial variation of the 740- to 1050-A data well from 100 to 130 km, but it does not fit the data well at higher altitudes; thus the presence of more rapidly absorbed shorter-wavelength radiation is indicated. This same resonance-scattering model yields Balmer-alpha intensities that result in good spatial agreement with the Balmer-alpha measurements, but a fivefold increase in the measured solar line center Lyman-beta flux is required (as required for the Lyman-beta measurement). The intensity ratio of Lyman-beta and Balmer-alpha at night is found to be a simple measure of the hydrogen optical depth if measurements with good accuracy can be made in the visible and ultraviolet spectrum.
Document ID
19720027233
Document Type
Reprint (Version printed in journal)
Authors
Weller, C. S.
Meier, R. R. (U.S. Navy, E. O. Hulburt Center for Space Research, Washington D.C., United States)
Tinsley, B. A. (Texas, University Dallas, Tex., United States)
Date Acquired
August 6, 2013
Publication Date
November 1, 1971
Publication Information
Publication: Journal of Geophysical Research
Volume: 76
Subject Category
GEOPHYSICS
Funding Number(s)
CONTRACT_GRANT: NSF GA-18767
CONTRACT_GRANT: NSR-44-004-041
Distribution Limits
Public
Copyright
Other