Contrasting Wave Power Intensity and Resource Quality in the Northwest Pacific: Variability, Availability, and Extreme Load Risk

ABSTRACT: Using 45 years of six-hourly ERA5 reanalysis data from 1979 to 2023, this study evaluates the spatial mismatch between theoretical wave-power intensity and practical resource quality across the Northwest Pacific. Resource quality is characterized by temporal variability, threshold-based availability, resource persistence, extreme-event exposure, and wind-sea/swell composition. The mid- to high-latitude storm belt and the Kuroshio Extension exhibit the highest mean and upper-tail wave power, but their resources are strongly concentrated in winter, with monthly coefficients of variation of approximately 0.5–0.7, seasonal variability indices commonly exceeding 0.7, and elevated extreme-event exposure. By contrast, subtropical and western-boundary transition regions generally have lower mean wave power but steadier availability and lower relative risk. Stable and low-risk regions are also more swell dominated, whereas high-resource and high-risk conditions are associated with larger wind-sea contributions. These results indicate that variability and risk can offset the benefits of high mean wave power and may increase operational costs. Maximum wave power, therefore, does not necessarily imply the highest resource quality, and the proposed framework provides a basis for basin-scale wave-energy pre-screening.