Wave Activity of Gravity Waves in the Mesosphere and Lower Thermosphere during a Meteorological Storm

The effect of a meteorological storm in October 2018 in the Baltic Sea on the state of the mesosphere and lower thermosphere is investigated. The wave activity of internal gravity waves from TIMED/SABER satellite data is analyzed, and the effects of the meteorological storm at heights of 80–100 km are determined. A method based on mode decomposition from SABER data is adapted to calculate the gravity wave potential energy density (GWPED) and to isolate the temperature perturbations caused by their propagation at lower thermospheric heights. Wavelet analysis of the temperature perturbations revealed two ranges of vertical wavelengths, 5–8 km and 14–18 km. In the area of a meteorological storm, the amplitude of internal gravity waves with vertical wavelengths of 5–8 km increases, and the area of their maximum expands and shifts upward to heights of ~90 km, while on meteorologically quiet days these waves are observed at heights of 65–70 km and with smaller amplitudes. Above the area of a meteorological storm at heights of 90–100 km, the values of the gravity wave potential energy density increase significantly compared to quiet days before and after the storm, and the spatial extent of the perturbation area increases.