### sea_surface_wave_mean_wavelength_from_variance_spectral_density_inverse_wavenumber_moment

under discussion
Created: Jan. 5, 2021
Proposer: Andy Saulter
Proposed Date: 2020-12-21
Change Date: Jan. 5, 2021, 3:57 p.m.
Term: sea_surface_wave_mean_wavelength_from_variance_spectral_density_inverse_wavenumber_moment
Unit: m
Unit ref: ULAA
AMIP:
GRIB:
The wave directional spectrum can be written as a five dimensional function S(t,x,y,k,theta) where t is time, x and y are horizontal coordinates (such as longitude and latitude), k is wavenumber and theta is direction. S has the standard name sea_surface_wave_directional_variance_spectral_density. S can be integrated over direction to give S1= integral(S dtheta) and this quantity has the standard name sea_surface_wave_variance_spectral_density. Wavenumber is the number of oscillations of a wave per unit distance. Wavenumber moments, M(n) of S1 can then be calculated as follows: M(n) = integral(S1 k^n dk), where k^n is k to the power of n. The inverse wave wavenumber, k(m-1), is calculated as the ratio M(-1)/M(0).
Change Date: Feb. 4, 2021, 4:29 p.m.
Term: sea_surface_wave_mean_wavelength_from_variance_spectral_density_inverse_wavenumber_moment
Unit: m
Unit ref: ULAA
AMIP:
GRIB:
The wave directional spectrum can be written as a five dimensional function S(t,x,y,k,theta) where t is time, x and y are horizontal coordinates (such as longitude and latitude), k is wavenumber and theta is direction. S has the standard name sea_surface_wave_directional_variance_spectral_density. S can be integrated over direction to give S1= integral(S dtheta) and this quantity has the standard name sea_surface_wave_variance_spectral_density. Wavenumber is the number of oscillations of a wave per unit distance. Wavenumber moments, M(n) of S1 can then be calculated as follows: M(n) = integral(S1 k^n dk), where k^n is k to the power of n. The inverse wave wavenumber, k(m-1), is calculated as the ratio M(-1)/M(0). The wavelength is the horizontal distance between repeated features on the waveform such as crests, troughs or upward passes through the mean level.