Stability and accuracy control in ocean wave model using stack filter

Numerical solution to the "third generation" ocean wave model using explicit scheme is found unstable when a large time integration step is used. Limiting the wave growth per time-step wit a reasonable range is successful in maintaining stability, but can produce large numerical error. By identifying the cause of instability, a stack filter is incorporated into the numerical model to eliminate the instability and allow the use of a large time step with acceptable accuracy. The saving in computational effort is significant.