# Swell spectrum and wind spectrum

While modelling both wind waves and swell waves, whether we have to add both spectra or append wind spectra in swell spectra? Because swell spectra has high amplitude values but wind spectra has very less amplitude than swell. Kindly guide me to model both swell waves and wind waves.

Although it is unclear which model(s) you are using, mathematically speaking:

Assuming that wind sea and swell are uncorrelated, combined wind sea and swell (total sea) can be described by a double peak frequency spectrum

$$S_{total}(\omega)=S_{ws}(\omega) + S_{swell}(\omega)$$

where $$S_{ws}(\omega)$$ is the wind sea spectrum and $$S_{swell}(\omega)$$ is the swell spectrum.

The spectral moments $$m_{n}$$ are additive

$$m_{n,total} = m_{n,ws} + m_{n,swell}$$

so e.g. combined significant wave height can be calculated as

$$H_{s,total} = \sqrt{H^{2}_{s,ws} + H^{2}_{s, swell}}$$

• Thank you for your response...I meant like this only... I studied some literatures in that also they add wind spectrum and swell spectrum... But I have doubt in that... While adding swell spectrum has high amplitude values but wind spectrum has less amplitude values... Is it ok to add those two spectrums? Thanks in advance Jun 29, 2023 at 13:17