Variability of the mesopause temperature and concentrations of reactive components of the mid-latitude atmosphere during sudden stratospheric warmings

Abstract

We investigated the variations in the temperature regime, atomic oxygen, and ozone concentrations during the 2013 January major sudden stratospheric warming (SSW) and the 2017 February minor SSW. Data from the spectrometric observations of the hydroxyl emission at the longitudinally spaced mid-latitude sites Tory (51.8° N, 103.1° E) and Zvenigorod (55.7º N, 36.8º E), SABER TIMED satellite measurements and MERRA reanalysis were analysed. Concentrations of the atomic oxygen and ozone at the OH emission layer were calculated by using experimental data on the emission intensity and rotational temperature of the OH molecule, photochemical model of OH radiation, and MSISE-E-90 model. Significant changes in the OH temperature and emission intensity, as well as in the concentrations of atomic oxygen and ozone during the SSWs were revealed. These effects may be caused by variations in the height of the hydroxyl emission layer due to the enhancement of vertical motion in the atmosphere during the SSW. We found an increase in the day-to-day variability of the mesopause temperature up to 3 times in comparison with the mean seasonal values. This may indicate the SSW-associated intensification of the manifestation of the traveling planetary waves activity in the upper atmosphere.