The visible airglow experiment—a review

Abstract

Contributions of the Visible Airglow Experiment (VAE) to the understanding of thermospheric aeronomy are summarized and discussed. The importance of instrumental design and operation is considered and particular attention is given to the relationship between observation and inversion for optical measurements of light emissions from a diffuse medium. The specific influence of the VAE investigation on the present understanding of the physical mechanisms which produce and destroy the excited species, O+(2P), O(ID), O(IS), N(2D), N+ (B2Z+), N2(C3rIu) and Mg+ (2P1/2), is discussed in detail.

Precursor to equatorial spread‐F in OI 630.0 nm dayglow

“…A unique dayglow photometer capable of retrieving faint emission features (0.1% of the background) in the presence of a bright background continuum[Narayanan et al 1989] was operated kom Waltair measuring OI 630.0 nm dayglow which originates fi'om 200-250 km altitude region with a layer semithickness of 50-75 km[Hays et al 1988]. This dayglow photometer employs a temperature-tuned narrow band (0.3 nm) interference filter, followed by a lowresolution (0.4ran FSR) Fabry-Perot(FP)etaloll pressure tuned to 630.0 rim.…”

Role of gravity wavelike seed perturbations on the triggering of ESF – a case study from unique dayglow observations

“…The measurements for the zenithal sky were made between 08:00 h and local sunset (18:00 h). The thermospheric O( 1 D) 630 nm emissions are typically centered at ∼220 km (Hays et al, 1988). The daytime OH emission intensity measurements were used to estimate the mesopause temperature.…”

Optical Aeronomy

“…The location of the peak emission and topside scale height contain neutral density and temperature information as well. Earlier work on 2P bands, particularly the (0,0) at 3371 Å, has been recently reviewed [ Hays et al , 1988; Meier , 1991]. Photoelectron flux calculations [ Richards and Torr , 1988; Lilensten , 1990] have been made which predict daytime electron impact ionization rates.…”

“…O 2 + is vibrationally quenched by interaction with oxygen atoms and removed primarily by recombination with electrons in the upper thermosphere, so the degree of vibrational excitation is approximately proportional to [ e ]/[O]. The resulting change in the O( 1 D ) production rate is very small [ Link and Cogger , 1988] and could not be verified by Yee et al [1988] using AE measurements. Their finding of a yield near unity, similar to many earlier results, is consistent with theory for O 2 + recombining from the v =1 and 2 levels.…”

“…Meier [1991] has also written a comprehensive review of ultraviolet emissions and their use for upper atmospheric analysis. Frank and Craven [1988] and Hays et al [1988] have reviewed results from the spin‐scan auroral imager on Dynamics Explorer‐1 (DE‐1) and the visible airglow experiment on Atmosphere Explorer (AE), respectively. Results from Antarctic studies are described by Eather [1988] and Rees [1989].…”