The U.S. Navy's Global Wind-Wave Models: An Investigation into Sources of Errors in Low-Frequency Energy Predictions
Abstract
This report describes an investigation to determine the relative importance of various sources of error in the two global-scale models of wind-generated surface waves used operationally by the U.S. Navy. The investigation is limited to low-frequency wave energy (e.g., less than 0.08 Hz). Sources of error are grouped into three broad categories: (1) wave model propagation numerics and resolution; (2) wave model physical formulations, and (3) wind forcing (provided to the wave model by an atmospheric model and/or data assimulation system. Each of the three is described and studied independently using tests and hindcasts of varying complexity. Based on these studies, it appears that in both of the Navy models, numerics and resolution are not first-order sources of error, and further suggests that, at present, more error is doe to model forcing than doe to physical formulation. The importance of accurately capturing the intensity of high-speed wind events is shown to be paramount. Also, it appears that the practical effect of physical formulations on swell in the two operational models is considerably different, whereas differences associated with the generation (low-frequency wave growth) stage are relatively modest between the two models.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 18, 2002
- Accession Number
- ADA408468
Entities
People
- Erick Erick Rogers
Organizations
- United States Naval Research Laboratory