Skill of Long-Range Forecasts of Ocean Wave Spectra from the Navy ESPC Version 2 System

Abstract: We report the outcome of evaluations of the skill of long-range forecasts from the ocean wave model component of the Navy's global coupled modeling system. Specifically, the model output is taken from a single member of the ensemble system, and we evaluate the skill of predicting seven model "wave height" parameters, computed from: energy in four frequency bands, energy in all bands combined, swell energy, and wind sea energy. The model is evaluated using two methods of "ground truth". The first is a new instrument for measuring wave spectra from space, Surface Waves Investigation and Monitoring (SWIM). The second is analyses from the same model. We propose a new method of band-wise bias correction of the observational dataset, using in situ wave observations, with the numerical wave model used as an intermediary.