Purpose. The aim of this study is to identify and analyze the main infrasonic oscillatory processes observed in records from sea level measuring stations and stations of global navigation satellite systems (GNSS), as well as to determine the primary sources of these oscillations.

Methods and Results. Ionospheric GNSS data from stations located in the Primorsky Territory of Russia and sea level data from marine stations in the Pacific Ocean and the Sea of Japan were analyzed. Variations in total electron content (TEC) and sea level were examined, and the dominant oscillation periods in the ionosphere and hydrosphere corresponding to specific measurement sites were compared. Spectral analysis was performed using two different methods: the periodogram method and the maximum likelihood estimation (MLE) method. The results show that the dominant oscillation periods in the ionosphere above water areas coincide with those of sea surface fluctuations, with an average deviation of 2.5%. Two independent experiments indicate that these oscillations originate in the atmosphere and subsequently excite oscillations of similar periods in the hydrosphere.

Conclusions. Analysis of ionospheric TEC variations and data from level measuring stations demonstrates that the periods of the dominant spectral maxima are in good agreement with high accuracy. The obtained results indicate that the oscillation periods the ionosphere and the hydrosphere correspond to the same eigen atmospheric oscillations over specific territories and water areas. The observed coincidence of oscillation periods confirms strong coupling between atmospheric infrasonic disturbances, the ionosphere, and the hydrosphere. In the future, integrated experiments with modern laser interferometric systems will allow for a better understanding of the mechanisms of interaction between geospheres.