wavespectra.construct.frequency.jonswap#

wavespectra.construct.frequency.jonswap(freq, fp, alpha=0.0081, gamma=3.3, sigma_a=0.07, sigma_b=0.09, hs=None, **kwargs)[source]#

Jonswap frequency spectrum for developing seas (Hasselmann et al., 1973).

Args:
  • freq (DataArray, 1darray, list): Frequency array (Hz).

  • fp (DataArray, float): Peak wave frequency (Hz).

  • alpha (DataArray, float): Phillip’s fetch-dependent scaling coefficient.

  • gamma (DataArray, float): Peak enhancement parameter.

  • sigma_a (DataArray, float): width of the peak enhancement parameter for f <= fp.

  • sigma_b (DataArray, float): width of the peak enhancement parameter for f > fp.

  • hs (DataArray, float): Significant wave height (m), if provided the Jonswap spectra are scaled so that \(4\sqrt{m_0} = hs\).

Returns:
  • efth (SpecArray): Jonswap spectrum E(f) (m2s).

Note:
  • If hs is provided than the scaling parameter alpha becomes irrelevant.

  • If two or more input args other than freq are DataArrays, they must share the same coordinates.