title: Atmospheric Physics and Earth Observations: Observations of Lyman-agr Emissions of Hydrogen and Deuterium.
abstract: A spectrophotometer was flown on Spacelab 1 to study various mechanisms of Lyman-alpha emission in the upper atmosphere. The use of absorption cells filled with H(2) and D(2) gases allowed us to discriminate a number of weak Lyman-alpha emissions heretofore masked by the strong H geocoronal emission due to resonance scattering of solar photons. Preliminary results are presented on three topics: the first optical detection of the deuterium Lyman-alpha emission at 110 kilometers, with an intensity of 330 rayleighs indicating an eddy diffusion coefficient of 1.3 x 10(6) square centimeters per second; auroral proton precipitations seen on both the night and the day side; and an emission located above 250 kilometers of altitude, interpreted as the result of charge exchange of magnetospheric protons with geocoronal atoms.
authors.forename: J L
authors.initials: JL
authors.lastname: Bertaux
authors.forename: F
authors.initials: F
authors.lastname: Goutail
authors.forename: G
authors.initials: G
authors.lastname: Kockarts