Temperatures in the upper mesosphere and lower thermosphere from OSIRIS observations of O₂ A-band emission spectra

Abstract

Temperatures in the mesosphere – lower thermosphere region (MLT) have been derived from the Optical Spectrograph and InfraRed Imaging System (OSIRIS) observations of O 2 A-band (b 1 Σ g + –X 3 Σ g – )O–O emission spectra. The observed OSIRIS spectra are inverted pixel by pixel, producing inverted volume emission rate spectra at altitudes between 90 and 110 km, which are compared to modelled temperature dependent O 2 A-band spectra. The estimated accuracy of the retrieved temperatures is approximately ±2 K near 90 km and up to ±6 K at higher altitudes. The developed temperature retrieval technique is presented, and some initial retrieval results are briefly discussed.