The temporal variability of the OH* airglow layer: A study based on Fourier Transform Spectroscopy and mesospheric models

Abstract

This work investigates the mesospheric OH* airglow layer. Ground-based observations of its Meinel emission are performed by means of Fourier Transform Spectroscopy at the AWIPEV station, Spitsbergen. Gas kinetic ambient temperatures are derived from the recorded spectra and compared with other data sets, indicating a rather persistent negative temperature offset to co-located spaceborne observations. Furthermore, temperature/brightness fluctuations serve as a diagnostic tool for wave driven perturbations of the OH* airglow layer due to its adiabatic/chemical response. Evidence of a vertical coupling with the lower atmospheric fraction is found on some occasions, corroborating current theories on the wave-mean-flow-interaction as the important driver of mesospheric dynamics. Finally, this work performed gas kinetic simulations, revealing the importance of the combined effect of the O and O2 quenching on the temporal modulation of vertical shifts between different OH* Meinel bands.