JONSWAP

The JONSWAP spectrum comes from the Joint North Sea Wave Project of the early 1970s and describes a fetch-limited, still-growing wind sea. It modifies the Pierson-Moskowitz form with a peak-enhancement factor (gamma, typically 3.3) that sharpens the spectral peak relative to a fully developed sea. JONSWAP is the standard design sea state in offshore and ship structural engineering and a default in spectral wave models.