# En:using ww3:2013 fall waves school:waves 201

De WAVEWATCH-III Wiki

# Foreword

This "waves 201" aims to make you understand what a wave model really does. You are expected to have taken series "waves 101" before, and may go on to "waves 301", which will be about actually running a model, and not an easy one: WAVEWATCH III.

# Course material

- wave action equation : basics on the wave action / energy balance. This lecture is 5 minutes from the start in this YouTube videp
- operational impact of source terms at NCEP : what it means in practice, a NCEP view.
- influence of source term parameterizations : from results with different parameterizations to a guide on how to design and tune parameterizations recorded on YouTube
- influence of forcing fields on model results : winds, currents, icebergs, from operational forecasts to reanalysis and the time consistency problem. YouTube video
- numerical choices and trade-offs for integrating the action balance equation : splitting (as in WW3) or non-splitting approaches (as in SWAN). Splitting errors, consequences of the Godunov theorem (negative energies, which are "renormalized" in SWAN) and Lax theorem (convergence problems). starts at 17 minutes into this same YouTube video

# Questions and answers

**Numerical issues and types of grid:** Caroline asked how much what was said about numerics applies to regular grid?
*Indeed the slides has "unstructured grids" in the title, but it is generally applicable to regular grids as well ... * to be continued