Limb view spectrum of the Earth's airglow

Abstract

Sometimes the Earth's airglow layer, when observed in the limb view, appears to be a double layer. During one of these occasions we were able to obtain absolute spectral intensity and altitude profiles for most well‐known airglow features from the space shuttle on the STS‐37 mission. The lower of the two airglow layers consisted of the OH Meinel bands, the ground state of the O2 atmospheric band at 762 nm and an intense nighttime sodium layer at 598 nm peaking near 92 km. The upper airglow layer consists of the atomic oxygen lines at 557.7, 630, and 636.4 nm, and a blue green continuum. Significant 557.7, 630, and 636.4 nm OI emissions were observed to extend above 110 km into the lower F region. The volume emission rate distribution as a function of altitude was modeled, and the model limb intensity distribution was compared to the data. From the spectral profile of the modeled volume emission distribution, the green continuum located at 103 km ± 2 km altitude was identified as recombination emission of NO2 produced by a dense NO layer. Another layer which was present at each of the modeled wavelength regions had a volume emission peak at 90 km. Our observations did not show the presence of continuum emission with increasing intensity toward the near infrared. The observed regions were quite near the equator.

On the dependence of the OH<sup>*</sup> Meinel emission altitude on vibrational level: SCIAMACHY observations and model simulations

“…Mende et al (1993) presented another study addressing the question, whether OH emissions from higher vibrational levels occur at higher altitudes. The authors used measurements taken with a grating spectrometer flown on the space shuttle (mission STS-37) in November 1990.…”

“…Furthermore, the main results of these studies are partly contradictory. Some model (McDade, 1991) and experimental studies (Mende et al, 1993) indicate that differences in emission peak altitudes for different vibrational levels are rather small. Other model (Makhlouf et al, 1995;Adler-Golden, 1997;Baker and Stair, 1988;Xu et al, 2012) and experimental results (Kaufmann et al, 2008;Xu et al, 2012) suggest a vibrational level dependence of the emission peak altitude of several km.…”

Dynamics of Neutral Wind in the polar region observed with two Fabry-Perot Interferometers

“…The heights of the 557.7-nm and 630.0-nm emission layers are generally thought to be about 110 km and 250 km, respectively (Sahai et al, 1990;Mende et al, 1993;Shepherd et al, 1995), but Vallance Jones et al (1991) reported that the peak height of 557.7-nm emission is about 125 km. Reflecting the uncertainty of the precise height of measurement, we shall refer to the 630.0-nm measurements as upper thermospheric winds and to the 557.7-nm measurements as lower thermospheric winds.…”

Global Observations of the 630-nm Nightglow and Patterns of Brightness Measured by ISUAL

“…The image reveals two distinct emission layers centered at different altitude levels. The upper emission is due to the OI( 1 D) airglow emission layer and the lower emission is due to the OH(9,3) airglow emission layer (Burnside et al 1977;Mende et al 1993). Rajesh et al (2009) suggested that most of the OH(9,3) enhancements observed by ISUAL were the result of the line-of-sight integration of the corresponding OI( 1 D) enhancements.…”