Equatorial airglow depletions induced by thermospheric winds
Interferometric observations on the 630.0 nm nightglow brightness at the equatorial station at Arequipa, Peru (16.2 S, 71.4 W geographic, 3.2 S dip latitude) have revealed widespread areas of airglow depletion, with reductions in intensity as large as factors of 3 or 4. These depletions correlated closely with large increases of the equatorward (northward) wind and the 630.0 nm kinetic temperature. On occasion, the usually small meridional wind reached a velocity of 100 m/s near 22h LT lasting for 1 to 2 hours. The temperature increases of 100K or more existed only in the poleware (southward) direction. Comparisons with modeling calculations suggest that this effect results from an upward movement of the ionosphere along the inclined magnetic field lines, driven by the equatorward neutral wind. The airglow column integrated emission rate is consequently decreased by the slower rate of formation and subsequent dissociative recombination of molecular oxygen ions within the higher F-layer. We conclude that the transient period of equatorward wind is a result of the passage of the midnight pressure bulge. (Author)
- Research Organization:
- Michigan Univ., Ann Arbor (USA). Space Physics Research Lab.
- OSTI ID:
- 6034165
- Report Number(s):
- AD-A-159787/1/XAB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
AIRGLOW
BRIGHTNESS
EQUATOR
IONOSPHERE
THERMOSPHERE
WIND
F REGION
INTERFEROMETRY
KINETICS
MAGNETIC FIELDS
MOLECULAR IONS
MOTION
OXYGEN
CHARGED PARTICLES
EARTH ATMOSPHERE
ELEMENTS
IONS
NONMETALS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PLANETARY IONOSPHERES
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena