Fluctuations of the Sea Level, Caused by Gravitational and Infra–Gravitational Sea Waves

Abstract

In the article we analyzed the results of processing experimental data of the range of surface gravity sea wind waves (2–20 s) and the range of infra-gravitational sea waves (30 s–10 min), obtained on the laser meter of hydrosphere pressure variations. The laser meter of hydrosphere pressure variations was installed for a long time on the bottom at different points of the Sea of Japan shelf. This paper presents the results of the analysis of swell waves caused by the KOMPASU typhoon, which passed over the Sea of Japan on 2–3 September 2010. Several mechanisms of the generation and propagation of waves with different periods during the typhoon movement are considered. In the course of the analysis, we studied the connection between variations of the main periods of gravitational sea waves with the dispersion and the Doppler effect, variations of speed and direction of the wind in a typhoon zone. The nonlinearity of the process of wave period change caused by dispersion is estimated. In the combined analysis of variations of hydrosphere pressure in the ranges of gravitational and infra-gravitational sea waves, we studied their energy relationships and determined regional infra-gravitational sea waves, which make a significant contribution to the energy of the infra-gravitational range.