Mesospheric temperature and atomic oxygen response during the January 2009 major stratospheric warming

The study examines the response of the mesosphere/lower thermosphere to the major stratospheric warming (SSW) event from January 2009, as seen in the OH and O2(0,1) atmospheric band airglow observations nominally at 87 and 94 km, respectively, by a SATI (Spectral Airglow Temperature Imager) instrument installed at the Polar Environment Atmospheric Research Laboratory (PEARL) at Eureka (80°N, 86°W) as part of the Canadian Network for the Detection of Atmospheric Change. At the time of the SSW, the airglow emissions and the derived rotational temperatures appear depleted and decreased, followed by an enhancement of the airglow emission rates during the SSW recovery phase, while the temperatures returned to their pre‐event state. An empirical relationship between OH airglow peak altitude determined by SABER (Sounding of the Atmosphere by Broadband Emission Radiometry) and SATI integrated emission rates allowed perturbed OH and O2(0,1) airglow altitudes to be assigned to the SATI observations. From these, the O volume mixing ratio (VMR), corresponding to the observed OH and O2(0,1) airglow emission rates were modeled. Atomic oxygen depletion by a factor of ∼5 was observed during the SSW and lasted for about 5 days. During the SSW recovery phase, the O VMR giving rise to the observed O2(0,1) airglow emission rates increased by a factor of 3.5 from its pre‐SSW level and 17 times from the peak of the SSW. Perturbations in the OH and O2(0,1) airglow layers with periods of 4, 6, 8, and 12 h indicate nonlinear interaction between zonally symmetric semidiurnal tides and planetary waves.