Tidal currents in the western Svalbard Fjords

Abstract

The paper is focusing on the tides and on the strong tidal current generated in the western fjords of Svalbard. Numerical model is chosen as a tool to study the barotropic tides. Model results are compared against measured sea level and drifters. Numerical modeling and observation of tides point that the tidal amplitude does not change strongly in these fjords but the tidal currents are enhanced in several locations, namely at the entrance to the Dickson Fjord, in the narrow passages in proximity to Svea, and in the central part of Van Keulenfjorden. As the strongest currents have been found at the passages at Akseløya Island we have focused our research on this location. The narrow northern channel (Akselsundet) at Akseløya is the main waterway to Svea coal mines. Tidal currents computed and observed at the northern tip of Akseløya Island can reach amplitude from 2 to 3 m s−1. Observation of the deployed drifters and calculation of the seeded particles in the passage at Akseløya depicted a complicated pattern of eddies. The jet-like currents and eddies are quite different at the ebb and flood tide phases. As the Akseløya Island orientation relative to the shore is different for the flood and ebb waters the flow through Akselsundet is differently constrained by this geometry. The observations show that the oscillating tidal motion causes large excursions of the water particle. The drifters released in the passage during flood ended up trapped in the eddy on the eastern side of the island.

Keywords

• Tides in Svalbard's fjords
• Numerical models
• Observation and model comparison
• Eddy motion and nonlinear effects