oa About Dynamic and Wave Processes in the Atmosphere According to Astrometry Observations with a Prism Astrolabe in Poltava

The purpose of the work is studying the dynamics of the atmosphere based on a long-term series of observations with a prism astrolabe in Poltava. Atmospheric processes can be defined in optical observations as changes in anomalous refraction. Parameters dφ/dt and du/dt are considered as indicators of dynamic processes, which characterize linear zenith displacements (LZD) during 2-hour intervals in the NS and EW directions. For the 52-year series of observations containing more than 10,000 groups, we have found that almost 50% of them exhibit statistically significant linear movements of the zenith (23% in the NS and 26% in EW directions). The connection of the parameters LZD with the position of the apparent zenith in the meridian direction shows that the observed zenith movements mainly reflect the process of oscillations of atmospheric layers around an equilibrium state. At the same time, for the 93 nights of observations, zenith movements were identified, as low-frequency waves with periods about of 6 hours and amplitudes sometimes reaching 0.5arcsec. We have defined also that the LZD parameters determined at the conditions of the atmospheric fronts passing were significant for more than half cases of such observations. And these cases can be interpreted, as registration of the internal gravity waves in the atmosphere. The obtained results of observations with a help of prism astrolabe prove that new modern ground-based telescopes, can serve as a full-fledged tool for studying of wave processes in the atmosphere.