Gravity wave-driven fluctuations in OH nightglow from an extended, dissipative emission region

Journal Article · Thu Aug 01 04:00:00 EDT 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/91JA00562· OSTI ID:5255971

Schubert, G; Walterscheid, R L ^[1]; Hickey, M P ^[2]

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1. Aerospace Corp., Los Angeles, CA (United States)
2. NASA Marshall Space Flight Center, Huntsville, AL (United States)

The theory of gravity wave-driven fluctuations in the OH nightglow from an extended source region is generalized to account for effects of eddy kinematic viscosity v and eddy thermal diffusivity {kappa}. In the nondiffusive case, the amplitudes and phases of vertically integrated normalized intensity ({delta}I)/({bar I}) and temperature ({delta}T{sub 1})/({bar T}{sub 1}) perturbations and vertically integrated Krassovsky's ratio ({eta}) as functions of period are influenced by the upper limit of vertical integration of the extended source, especially at long periods when vertical wavelengths {gamma}{sub v} are small. The effects, which include oscillations in ({delta}T)/({bar I}), ({delta}T{sub 1})/({bar T}{sub 1}), and ({eta}), particularly at long periods, are due to constructive and destructive interference of nightglow signals from vertically separated levels of the OH emitting region that occur when {gamma}{sub v} is comparable to or smaller than the thickness of the main emission region. The sensitivity of these ratios to the upper limit of vertical integration occurs because of the relatively small rate of decay of the intensity of OH emission with height above the peak emission level and the exponential growth with altitude of nondissipative gravity waves. Because eddy diffusion increases {gamma}{sub v}, especially at long periods, and reduces wave growth with height compared with the case v = {kappa} = 0, inclusion of eddy diffusion removes the sensitivity of ({eta}) and the other ratios ot the maximum height of vertical integration. It is essential to account for both eddy diffusion and emission from the entire vertically extended emission region to correctly predict ({eta}), ({delta}I)/({bar I}), and ({delta}T{sub 1})/({bar T}{sub 1}) at long gravity wave periods.

• OSTI ID: 5255971
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:A8; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AIRGLOW
AMPLITUDES
CHEMISTRY
FLUCTUATIONS
GRAVITY WAVES
HYDROXYL RADICALS
MATHEMATICAL MODELS
MODULATION
ORIGIN
OSCILLATIONS
PHYSICAL PROPERTIES
RADICALS
THERMAL DIFFUSIVITY
THERMODYNAMIC PROPERTIES
VARIATIONS