A study of mid-latitude 5577[angstrom] OI dayglow emissions

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7042341

Hume, Jr, E E

The green line (5577[angstrom]) is a bright, persistent component of the visible airglow produced by an electric quadrupole transition from the meta-stable second excited state ([sup 1]S[sub 0]) to the first excited state ([sup 1]D[sub 2]) of atomic oxygen. In this thesis, production and loss mechanisms important to the F-region dayglow 5577[angstrom] emission are investigated. Four major source reactions need to be incorporated in the modeling of the emission profile, photoelectron impact on atomic oxygen, dissociative recombination of O[sup +][sub 2], quenching of N[sub 2](A[sup 3][Sigma][sub u][sup +]) by atomic oxygen, and photo-dissociation of O[sub 2]. For some of the reactions, the properties of the rate coefficients, branching ratios, and cross sections are not well known. Models are used to determine the rate coefficients, branching ratios, and cross sections for these reactions. The impact of photoelectrons on atomic oxygen is the primary source of 5577[angstrom] dayglow emission in the thermosphere. The quenching of N[sub 2](A) by atomic oxygen is an important source of the 5577[angstrom] emission at the peak in the layer. The total quenching rate was determined using a vibrational model and a band model for N[sub 2] to study emissions at 3371[angstrom] from the Atmosphere Explorer satellite. The value of the rate coefficient deduced here agrees well with experimental values by Piper and Caledonia (1981) and Thomas and Kaufman (1985). The effective branching ratio determined by this study tends to support the results from Piper (1982) and De Souza et al. (1985). The effect of the distribution of the vibrational population of the N[sub 2](A[sup 3][Sigma][sub u][sup +]) state on the branching ratio is also discussed. The extension of the dayglow photochemistry into the twilight is also investigated. The model developed for the dayglow can reasonably reproduce the rapidly changing twilight emissions.

• Research Organization: Michigan Univ., Ann Arbor, MI (United States)
• OSTI ID: 7042341
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500 -- Photochemistry
54 ENVIRONMENTAL SCIENCES
540110
661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AIRGLOW
BRANCHING RATIO
CHEMICAL REACTIONS
CROSS SECTIONS
E2-TRANSITIONS
EARTH ATMOSPHERE
ELEMENTS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
F REGION
GEOGRAPHICAL VARIATIONS
IONOSPHERE
LATITUDE EFFECT
MATHEMATICAL MODELS
MULTIPOLE TRANSITIONS
NONMETALS
OXYGEN
PHOTOCHEMICAL REACTIONS
PLANETARY IONOSPHERES
VARIATIONS
VIBRATIONAL STATES