Wave Climate Patterns from Spatial Tracking of Global Long-Term Ocean Wave Spectra

Long-term wave spectral statistics can provide a better description of wave climate than integrated wave parameters because several wave climate systems (WCSs) generated by different wind climate systems can coexist at the same location. In this study, global wave climate patterns are presented by spatially tracking point-wise long-term wave spectra (probability density distributions of wave spectral partitions) from a WAVEWATCH III hindcast, providing new insights into global wave climate. Tens of well-defined WCSs, which are generated in different source regions by different wind systems, including prevailing westerlies, polar easterlies, trade winds, and monsoons, were identified. These WCSs are independent of each other because wave systems from different origins travel independently. The spatial distributions of these WCSs can illustrate the entire life cycle of ocean waves, from being generated as dominant wind-seas to becoming less dominant swells in far fields, from a climatic point of view. The mean wave directions in WCS patterns, especially those in westerlies-generated WCSs, are generally in agreement with the great circles on Earth's surface, which display the propagation routes of ocean swells.