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Interpretation of Ogo 5 Lyman alpha measurements in the upper geocorona

1973; American Geophysical Union; Volume: 78; Issue: 1 Linguagem: Inglês

10.1029/ja078i001p00080

2156-2202

Jean‐Loup Bertaux, J. É. Blamont,

Scientific Research and Discoveries

Journal of Geophysical Research (1896-1977)Volume 78, Issue 1 p. 80-91 Interpretation of Ogo 5 Lyman alpha measurements in the upper geocorona J. L. Bertaux, J. L. BertauxSearch for more papers by this authorJ. E. Blamont, J. E. BlamontSearch for more papers by this author J. L. Bertaux, J. L. BertauxSearch for more papers by this authorJ. E. Blamont, J. E. BlamontSearch for more papers by this author First published: 1 January 1973 https://doi.org/10.1029/JA078i001p00080Citations: 47AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Abstract Lyman α intensity measurements (1216 A) were obtained by a photometer on board the Ogo 5 spacecraft outside the geocorona. The Lyman α emission originating from hydrogen atoms in the upper part of the geocorona was derived from the total measured intensity after subtraction of the extraterrestrial emission. The hydrogen density distribution between 5 and 16 RE was deduced. This distribution is consistent with the evaporative atmospheric model of J. W. Chamberlain on the night side. A depletion of atoms found above a distance of 6 RE on the day side could be accounted for by the action on satellite particles of charge exchange with solar wind protons and by the solar Lyman α radiation pressure, according to numerical computations of both effects. It was also calculated that orbits with a perigee of 2 RE are rapidly distorted by radiation pressure. The mean time spent in the exosphere by satellite particles on such orbits is only 5 × 105 sec, one-half the ionization lifetime. References Bertaux, J. L., J. E. Blamont, Ogo 5 measurements of Lyman alpha intensity distribution and line width up to 6 earth radii, Space Res., 10, 591, 1970. Bertaux, J. L., J. E. Blamont, Evidence for a source of an extraterrestrial hydrogen Lyman alpha emission: The interstellar wind, Astron. Astrophys., 11, 200, 1971. Blamont, J. E., A. Vidal-Madjar, Monitoring of the Lyman alpha emission line of the sun during the year 1969, J. Geophys. Res., 76, 4311, 1971. Brandt, J. C., J. W. Chamberlain, Interplanetary gas, 1, Hydrogen radiation in the night sky, Astrophys. J., 130, 670, 1959. Chamberlain, J. W., Planetary coronae and atmospheric evaporation, Planet. Space Sci., 11, 901, 1963. Hinteregger, H. E., Interplanetary ionization by solar extreme ultraviolet radiation, Astrophys. J., 132, 801, 1961. Jacchia, L. G., Revised static models of the thermosphere and exosphere with empirical temperature profilesSpec. Rep. 332Smithson. Astrophys. Obser, Cambridge, Mass., 1971. Kurt, V. G., S. B. Dostovalow, E. K. Scheffer, The Venus far ultraviolet observations with Venera 4, J. Atmos. Sci., 25, 668, 1968. McAfee, J. R., The effect of lateral flow on exospheric densities, thesis, Univ. of Pittsburgh, Pittsburgh, Pa., 1965. Mange, P., R. R. Meier, Ogo 3 observations of the Lyman-alpha intensity and the hydrogen concentration beyond 5 RE, J. Geophys. Res., 75, 1837, 1970. Thomas, G. E., Lyman alpha scattering in the earth's hydrogen geocorona, J. Geophys. Res., 68, 2639, 1963. Thomas, G. E., R. C. Bohlin, Lyman-alpha measurements of neutral hydrogen in the outer geocorona and in the interplanetary space, J. Geophys. Res., 77, 2752, 1972. Thomas, G. E., R. F. Krassa, Ogo-5 measurements of the Lyman-alpha sky background, Astron. Astrophys., 11, 218, 1971. Vidal-Madjar, A., J. L. Bertaux, A calculated hydrogen distribution in the exosphere, Planet. Space Sci., 20, 1147, 1972. Wallace, L., C. A. Barth, J. B. Pearce, K. K. Kelly, D. E. Anderson Jr., W. G. Fastie, Mariner 5 measurement of the earth's Lymanalpha emission, J. Geophys. Res., 75, 3769, 1970. Citing Literature Volume78, Issue1Space Physics1 January 1973Pages 80-91 ReferencesRelatedInformation