A Stokes drift approximation based on the Phillips spectrum

- A new Stokes profile parameterization based on the Phillips profile.
- The profile is a much better match than the monochromatic profile.
- The shear is also much closer to the shear under the full spectrum.
- The profile requires only the Stokes surface drift and transport.

A new approximation to the Stokes drift velocity profile based on the exact solution for the Phillips spectrum is explored. The profile is compared with the monochromatic profile and the recently proposed exponential integral profile. ERA-Interim spectra and spectra from a wave buoy in the central North Sea are used to investigate the behavior of the profile. It is found that the new profile has a much stronger gradient near the surface and lower normalized deviation from the profile computed from the spectra. Based on estimates from two open-ocean locations, an average value has been estimated for a key parameter of the profile. Given this parameter, the profile can be computed from the same two parameters as the monochromatic profile, namely the transport and the surface Stokes drift velocity.