JONSWAP Wave Spectra
In 1968 and 1969 an extensive wave measurement program, known as the Joint North Sea Wave Project (JONSWAP) was carried out along a line extending over 100 miles into the North Sea from Sylt Island. Analysis of the data yielded a spectral formulation for fetch-limited wind generated seas.
The following definition of a Mean JONSWAP wave spectrum is advised by the 17th ITTC in 1984 for fetch limited situations: