Remarks on the use of ‘diffusion diagrams’ in modeling scale-dependent diffusion

An empirical relationship between an apparent diffusivity and the scale of diffusion can be used in numerical modeling for oceanic dispersion. Some care must be exercised primarily because the diffusivity and the diffusion scale are usually defined somewhat arbitrarily. On the basis of the diffusion equation with a scale-dependent diffusivity, it is shown that the proper formula may differ numerically by an order of magnitude from the empirical relation.