Oceanographic coastal currents over bottom slopes

Laboratory experiments simulating gravity-driven oceanographic coastal surface currents are described. Results from three complementing studies are discussed and compared to a new geostrophic model. The first study was conducted in a small-scale (1m diameter) water-filled rotating tank. The other two studies were carried out at the large-scale Coriolis turntables at Grenoble (13m tank diameter) and Trondheim (5m tank diameter). The height, the width and the length of the currents are studied as a function of the relevant independent experimental parameters. The small-scale experiments and the Grenoble study focused on currents flowing along a vertical coastline in an effectively infinitely deep ocean. The Trondheim study generalized these results by investigating how the dynamics are affected when the currents flow along inclined coastlines with different bottom slopes. The data for vertical-wall and inclined-wall currents are compared to each other. Preliminary results obtained from computational simulations of the currents employing the SINMOD model developed at SINTEF are presented. A typical current as observed in a small-scale experiment is shown in Figure 1 and a simulated current is displayed in Figure 2. It can be seen that experiment and computation are already in good qualitative agreement