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An analysis of satellite observations of the O I EUV dayglow

Journal Article · · Journal of Geophysical Research; (United States)
;  [1];  [2];  [3]
  1. Univ. of California, Berkeley (United States)
  2. Univ. of Colorado, Boulder (United States)
  3. York Univ., North York, Ontario (Canada)
An analysis of satellite STP78-1 measurements at solar maximum of the latitudinal variation of O I EUV dayglow emissions at 1,356, 1,304 and 989 {angstrom} is presented. The dayglow intensity measurements corroborated by Atmosphere Explorer-E data indicate that the exospheric temperature was about 220-244 K higher than predicted by the MSIS-83 thermospheric model. In addition, the temperature variation with latitude is not as large as predicted by MSIS-83 for day 80, 1979. The 1,304- and 1,356-{angstrom} intensity measurements are consistent with electron impact excitation cross-section measurements of Zipf and Erdman (1985). The 989-{angstrom} excitation cross of Zipf and Erdman (1985) requires a branching ratio of 7.10{sup {minus}4} for transitions other than 989-{angstrom} in order to produce agreement with the data. The Vaughan and Doering (1987) direct 3s{prime} {sup 3}D{sup o} excitation cross section, about a factor of 3 smaller than the optical excitation cross section of Zipf and Erdman (1985), is also compatible with our 989-{angstrom} data for a branching ratio near 1x10{sup {minus}4}. The solar 1,304-{angstrom} spectral irradiance inferred from the observations is about a factor of 2 lower than the rocket measurements of Mount et al. (190/80), but is consistent with Solar Mesosphere Explorer results. The measurements also suggest that enhancement of the 1,304-{angstrom} electron impact excitation cross section due to radiative entrapment of cascade-feeding photons is negligible.
OSTI ID:
5862208
Journal Information:
Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 93:A4; ISSN JGREA; ISSN 0148-0227
Country of Publication:
United States
Language:
English