Tidal external files using FFT #56
Description
We have updated the tidal dissipation parameterisation using a polynomial fitting method. An alternative approach based on a Fourier method, developed by @luweiyang, is currently a WIP and documented in the same issue. Some concerns regarding the implementation have been raised in this comment: #53 (comment).
Unlike previous methods that downsample high-res bathymetry (e.g., from 25 km to 100 km), this implementation operates directly on the model grid. This allows for the estimation of bottom roughness and potentially other quantities such as drag coefficients without compromising key information. The structure follows the same framework as the existing polynomial fitting method.