@article{fdi:010062015,
  title = {{A} numerical model for free infragravity waves : definition and validation at regional and global scales},
  author = {{A}rdhuin, {F}. and {R}awat, {A}. and {A}ucan, {J}er{\^o}me},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he spectral wave model {WAVEWATCH} {III} is extended from the windsea and swell band to lower frequencies, in order to represent free waves in the infragravity ({IG}) wave band. {T}his extension is based on an empirical source of {IG} energy, which is defined along shorelines from the significant wave height and a mean period. {T}he empirical proportionality factor is found to reproduce accurately the variations of free {IG} wave energy in coastal areas, where it was calibrated, and also has a good skill at global scales. {I}n the open ocean, the model is particularly verified for frequencies in the range 5 to 14 m{H}z for which ocean bottom records are sensitive to the {IG} signal. {T}he model captures between 30% and 80% of the variance in {IG} wave heights, depending on location, and reproduces the mean {IG} energies within 50%. {W}here the model reproduces best the {IG} variability, it can be used to fill in the gaps between recording stations, providing a first view of the global {IG} wave field. {O}ur first application is the estimation of the surface gravity wave contribution to the surface elevation spectra that will be measured by the {S}urface {W}ater {O}cean {T}opography ({SWOT}) satellite mission. {T}he actual contribution of {IG} waves on measured along-track wavenumber spectra varies with the cross-track averaging method. {T}ypically, the strongest {IG} signal is expected to occur for wavelengths between 2 and 10 km. {F}or a given region, the spectral level at 10 km wavelength are not very sensitive to the local depth in the range 200 to 5000 m. {A}t this wavelength, and on the east side of all mid-latitude ocean basins, the median spectral density associated to free {IG} waves is of the order of 0.4 cm(2)/(cycle/km), equal to the expected quasi-geostrophic signature of surface currents. {IG} spectra rise above 4 times this level for 16% of the time. {E}ven at 20 km wavelength, spectral levels above 1 cm(2)/(cycle/km) are likely to occur more that 10% of the time for some oceanic regions.},
  keywords = {{I}nfragravity waves ; {SWOT} ; {S}pectral model},
  booktitle = {},
  journal = {{O}cean {M}odelling},
  volume = {77},
  numero = {},
  pages = {20--32},
  ISSN = {1463-5003},
  year = {2014},
  DOI = {10.1016/j.ocemod.2014.02.006},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062015},
}