A Detailed Comparison of a Range of Three-Dimensional Models of theM2Tide in the Faeroe–Shetland Channel and Northern North Sea

Abstract

Abstract A three-dimensional hydrodynamic model of the Faeroe–Shetland Channel and northern North Sea is used to investigate the spatial variability of M2 tidal elevations and currents in the region. This area is chosen because it covers a range of water depths. Also, there is a significant database of tidal elevations (namely 41 gauges) and current meters (namely 89 observations) with which comparisons can be made. With the exception of a couple of measurements made at the shelf edge, which may be influenced by the internal tide, namely a 180° phase shift across the thermocline due to a first mode internal tide, the observations correspond to those of a barotropic tide. Two different approaches are used to represent the profile of tidal currents in the vertical. In the first a spectral/functional method is used, while in the second a finite difference grid is applied. A range of parameterizations of vertical eddy viscosity (suitable for deep water regions) are used, from ones in which viscosity is relate...