Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “DAYGLOW”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1969

Escaping photoelectron and dayglow.

Dayglow O I lambda 1304 and 1356 A radiations photoelectron excitation rates theoretical calculation and experimental data on altitude dependence characteristics

Prasad, S. S.↗
NASA NTRS1972

Resonance scattering of the first positive system of N2 in the dayglow.

Rocket measurements of the differential photoelectron flux and the volume emission rate of the N2(0, 0) second positive band are used to calculate the daytime concentration of metastable A(super 3)Sigma(sub u)+ molecules, and consequently the resonance scattering contribution to the N2 first positive emission in the dayglow. The dominant source of N2 first positive emission is found to be photoelectron impact, with resonance scattering contributing only 10-20 per cent the total emission.

Feldman, P. D.↗
NASA NTRS1976

A rocket measurement of the extreme ultraviolet dayglow

Extreme ultraviolet spectra of the mid-latitude dayglow in the wavelength range of 550 to 1250A have been obtained with a rocket borne grating spectrometer at a resolution of 20A. Spectra were obtained in the altitude range of 140 to 280 km. The spectra are dominated by emissions from atomic multiplets and no molecular bands have been identified with certainty. The strongest emissions other than H Lyman-alpha are OI (989) and OII (834). Other prominent emissions include He I(584), N II(916) and N II(1085). An unexpected feature near 612A has an intensity comparable to He I(584).

Christensen, A. B.↗
NASA NTRS1976

Detection of O2 dayglow emission from Mars and the Martian ozone abundance

High-resolution spectroscopy of Mars in the vicinity of 1.27 microns has revealed the presence of emission lines of O2 which are interpreted as the result of production of O2(1 delta g) in the ultraviolet photolysis of Martian ozone. In the equatorial region of Mars, the dayglow intensity implies an ozone abundance near 0.2 microatm, which seems consistent with theoretical models which utilize the measured water-vapor abundance. A much larger ozone abundance exists in the atmosphere at high winter latitude, in agreement with direct measurement of ozone absorption performed by the Mariner spacecraft.

Noxon, J. F.↗
NASA NTRS1979

The latitude variation of O2 dayglow and O3 abundance on Mars

Spectroscopic observations of the Martian O2 dayglow near 1.27 microns directly show that the parent molecule, O3, has a strong latitude variation. These measurements give actual data on the equatorial concentrations, where Mariner gave only upper limits. The data also agree with a recent photochemical model, and the derived atmospheric temperature is in good agreement with this model.

Traub, W. A.↗
NASA NTRS1980

The ultraviolet dayglow. I - Far UV emissions of N and N2

Far ultraviolet rocket spectra of N I and N2 dayglow emissions have been analyzed by using AE-E photoelectron spectra, laboratory-measured excitation cross sections, and photochemical models of atomic nitrogen. A self-consistent picture of both optically thick and thin emission features is found by using a model in which the principal production mechanism for N I 1200-A and 1493-A photons is photodissociative excitation of N2. The aeronomic data require that 50-70% of the excited 4 P atoms produced dissociatively have velocities within the Doppler core of the ambient nitrogen atoms, contrary to the expectation that those atoms are produced with large excess kinetic energy. The derived atomic nitrogen density has a maximum density of 2.7 x 10 to the 7th per cu cm at 170 km, a value that is within 40% of that from recent models of odd nitrogen photochemistry.

Meier, R. R.↗