Seasonal features of the spatial distribution of atmospheric gravitational waves in the Earth’s polar thermosphere

Vlasov, DI, 1Fedorenko, AK, Kryuchkov, EI, 1Cheremnykh, OK, 1Zhuk, IT
1Space Research Institute under NAS and National Space Agency of Ukraine, Kyiv, Ukraine
Kinemat. fiz. nebesnyh tel (Online) 2022, 38(2):23-38
https://doi.org/10.15407/kfnt2022.02.023
Start Page: Dynamics and Physics of Solar System Bodies
Language: Ukrainian
Abstract: 

Features of the spatial distribution of atmospheric gravity waves (AGW) in the polar thermosphere Earth were investigated. Research is based on data of the direct satellite measurements of the neutral atmosphere parameters. AGW is systematically observed in the polar regions of both hemispheres according to the analyzed data. Amplitudes of the AGW in these regions are usually much greater than the amplitudes of the waves in the middle and low latitudes. At the same time polar AGW with large amplitudes are registered against the background of high-velocity spatially inhomogeneous wind flows that indicate their possible amplifying due to interaction with the wind. Based on the analysis of measurement data on the Dynamics Explorer 2 satellite, the relationship between the spatial distribution of atmospheric gravitational waves and the auroral oval was revealed. Seasonal regularities in the distribution of the wave field over the Antarctic and the Arctic have been established on a large volume of experimental data. A comparative analysis of the features of AGW in the polar thermosphere of both hemispheres was carried out for the conditions of the polar day and polar night. Some differences in the distribution of AGW depending on the Кр-index are noticed. It has been suggested that the observed seasonal features of the AGW distribution and its dependence on the level of geomagnetic activity are associated with the restructuring of the polar wind circulation when the conditions of solar illumination and geomagnetic conditions change.

Keywords: atmospheric gravity wave, polar thermosphere, satellite measurement