Seasonal variations of the nighttime O(¹S) and OH (8‐3) airglow intensity at Adelaide, Australia

Abstract

We analyze 15 years of atomic oxygen (OI) 558 nm and hydroxyl (OH) (8-3) 730 nm nightglow emission intensities from heights near 96 and 87 km, respectively, measured using filter photometers at the Buckland Park Field Station (34.6°S, 138.6°E) near Adelaide, Australia. The intensity of both emissions exhibits clear seasonal and interannual periodicities, with annual, semiannual, and quasi-biennial oscillations, as well as a solar cycle influence. In addition, there is a terannual and 4.1 year component in the OI airglow intensity and both a quasi-biennial and quasi-triennial oscillation in the OH intensity. The results are in very good agreement with simultaneous collocated measurements made with an imager, and with global satellite climatologies of OI and OH intensities reported for the Wind Imaging Interferometer instrument. The mean value of the OI annual oscillation intensity is the same as that of the semiannual oscillation at this location to within the experimental uncertainty. The OI annual oscillation maximizes in summer, and the semiannual oscillation maximizes in autumn and spring, with the largest maximum in autumn. The terannual component in the OI nightglow maximizes in early summer, autumn, and spring. The quasi-biennial oscillation in the OI nightglow takes its first maximum value in autumn 1996, and the 4.1 year period in this emission first maximizes in summer 1998. The OH annual and semiannual oscillation intensities also agree to within the experimental uncertainties and are observed to peak in early winter. The quasi-biennial and quasi-triennial oscillations in this emission take their first maximum value in summer 1996.

Updated Long‐Term Trends in Mesopause Temperature, Airglow Emissions, and Noctilucent Clouds

“…Several reviews (Beig, ; Beig et al, ; Beig et al, ) demonstrate the temperature response of 4–5 K per 100 F10.7 solar flux units (1 sfu=10 −22 · W·m −2 · Hz −1 ) at midlatitudes, which have been confirmed by recent studies (Kalicinsky et al, ; Noll et al, ; Perminov et al, ). Also, airglow emission intensities have a positive response to the solar cycle, with 6–28% per 100 sfu depending on the season and latitude (Gao et al, ; Noll et al, ; Reid et al, ; Teiser & von Savigny, ).…”

Seasonal MLT-region nightglow intensities, temperatures, and emission heights at a Southern Hemisphere midlatitude site

“…Reid et al (2014) have also noted that at Adelaide there is a striking correspondence between the O 2 (0-1) temperature maximum, the time of greatest O( 1 S) brightness (Reid and Woithe, 2007), and the time of the maximum meridional wind, which would correspond to the downward phase of the diurnal tide at equinox later in the night. This is consistent with the transport of atomic oxygen down into the MLT region and the brightening of the O( 1 S) and OH(8-3) airglow late in the night as observed at the autumnal equinox.…”

“…In addition to the Czerny-Turner spectrometer and meteor radar, which we describe below, the instruments of most interest to this work are the 3FP and the Aerospace Imager. The 3FP has been described by Woithe (2000), Ding et al (2004), Woithe (2005, 2007), and Reid et al (2014). It measures the intensity of the O( 1 S) 558 nm and OH(8-3) 730 nm airglow emission every minute at night, during moon-free cloudless periods.…”

“…To quantify the variation of the temperature and intensity data through the night, we follow Reid et al (2014) and divide the period between 18:00 and 06:00 LT into four 3 h blocks of data. We then analyse each 3 h data block using a Lomb-Scargle periodogram to determine the dominant periods present.…”

“…In the case of the O 2 , there is stronger agreement in form, in this case, a dominant SAO, maximising at the equinoxes. Reid et al (2014) considered a long series of observations of the OH(8-3) and O( 1 S) intensities made at Buckland Park, and shown on these plots are the 3FP OH(8-3) and O( 1 S) intensities from their work corresponding to the same observational period. The agreement in form is good in the case of the OH results and strong in the case of the O 2 (0-1) and O( 1 S) results.…”