CHARACTERISTICS OF UNDER-ICE OCEAN CURRENTS MEASURED DURING WAVE PROPAGATION EVENTS IN THE BARENTS SEA

摘要

The propagation of surface waves in ice-covered waters can produce significant changes in the structure of floating ice over relatively short time periods and over very large open water areas. The effect is controlled by wave speeds and wave energy dissipation in ice conditions. Investigations of under-ice currents were performed during the expeditions by the RV Mikhail Somov (Russia) and the RV Lance (Norway). Turbulent characteristics of the currents were studied using data obtained from an Acoustic Doppler Velocimeter (ADV) SonTek Hydra 5MHz installed underneath the drifting ice in a downward-looking position. In 2014, the swell was also recorded using a Datawell buoy installed on the drifting ice. Despite a relatively long period of observations, only four events of wave propagation were registered and analyzed. In most of the events the dominant wave period was around 12 seconds. The influences of turbulent characteristics of under-ice currents and ice drift on the energy dissipation rates of waves propagating below continuous ice cover are investigated in the present paper.