Spectral points in WW3

[AlexCrls]

I am running the WW3 model using a two-way nesting configuration, with point outputs defined inside the nested grid. After post-processing out_pnt.ww3, the model generates a NetCDF file containing the point spectral data, from which I obtain wave energy, directions, and frequencies.

When I compare the significant wave height (Hs) extracted directly from the model grid (NetCDF field output) with the Hs computed from the wave spectrum at the same point, I find that the spectral Hs can be either higher or lower than the grid-based Hs.

My question is not about how WW3 defines or integrates Hs, but rather about how the model extracts the wave spectrum at point locations.

I would appreciate any guidance or references to the relevant documentation or source code sections describing the point spectral extraction process in WW3.

Regards

[mickaelaccensi]

Hi Alex,

The output points are obtained by bi-linear interpolation from the spectra at the grid points. Given the possibility of ice coverage, the actual interpolation factors can only be determined at the actual output time.

Best,

Mickael