Wave Modelling (WAM)

Background

The WAM wave model is a 3rd generation wave model, developed by the Wave Model Development and Implementation Group (WAMDI, 1988). It was developed to resolve known issues with first generation wave models (which erroneously used a non-existent universal high-frequency equilibrium wave spectrum) and second generation wave models (which could not properly simulate complex wave fields generated by rapidly changing winds, as for example occurs with hurricanes, small-scale cyclones or fronts).

Model details

The WAM model is a 3rd generation model which integrates the basic transport equation describing the evolution of a two-dimensional ocean wave spectrum without additional unplanned assumptions regarding the spectral shape. There are three explicit source functions which describe the wind input, non-linear transfer and whitecapping dissipation. There is an additional bottom dissipation source function and refraction terms are included in the finite-depth version of the model. The model runs on a spherical latitude-longitude grid and can be used in any ocean region.

WAM predicts directional spectra along with wave properties such as significant wave height, mean wave direction and frequency, swell wave height and mean direction, and wind stress fields corrected by including the wave induced stress and the drag coefficient at each grid point at chosen output times.

WAM can be coupled to a range of other models. Examples include the South East Asian Ocean Model (SEAOM), the Proudman Oceanographic Laboratory Coastal Ocean Modelling System ( POLCOMS ), the Nucleus for European Modelling of the Ocean model (NEMO), the High Resolution Limited Area Model (HIRLAM) model and the National Center for Atmospheric Research (NCAR) Regional Climate Model (RegCM).

References

The following papers are examples which show the capabilities of the WAM model. Numerous other publications based on WAM outputs are available in the scientific literature.

Bargagli, A., A. Carillo, G. Pisacane, P. M. Ruti, M. V. Struglia, N. Tartaglione, 2002. An Integrated Forecast System over the Mediterranean Basin: Extreme Surge Prediction in the Northern Adriatic Sea. Monthly Weather Review, 130, 1317-1332.

Bauer, E., Hasselmann, K., Young, I.R., Hasselmann, S., 1996. Assimilation of wave data into the wave model WAM using an impulse response function method. Journal of Geophysical Research, 101(C2), 3801-3816.

Komen, G.J., Cavaleri, L., Donelan, M., Hasselmann, K., Hasselmann, S., Janssen, P.A.E.M., 1994. Dynamics and modelling of ocean waves. Cambridge University Press, Cambridge, 532pp.

Monbaliu, J., Padilla-Hernández, R., Hargreaves, J.C., Carretero-Albiach, J.C., Luo, W., Sclavo, M., Günther, H., 2000. The spectral wave model WAM adapted for applications with high spatial resolution. Coastal Engineering, 41(1-3), 41-62.

The WAMDI Group, 1988. The WAM Model - A Third Generation Ocean Wave Prediction Model. Journal of Physical Oceanography, 18, 1775-1810

Further information

For further information on WAM, please contact a member of staff from the NOC Marine Systems Modelling Group .