Wave Period Parameters

Mean Period Total Swell | Mean Period Wind Waves | Mean Wave Period

Mean Period Total Swell

Spectral mean wave period obtained using the reciprocal frequency moment of the total swell spectrum. The total swell spectrum is obtained by only considering the components of the two-dimensional wave spectrum that are not under the influence of the local wind.

mean_period_total_swell:s

Examples

• Create a time series showing the mean period of the total swell. The queried location lies in the Philippine Sea south of Nagasaki.https://api-mm.ncm.gov.sa/2025-07-17T00:00:00ZP3D:PT1H/mean_period_total_swell:s/27.852903,130.116770/html

• https://api-mm.ncm.gov.sa/2025-07-17T00:00:00Z/mean_period_total_swell:s/90,-180_-90,180:1000x600/html

Mean Period Wind Waves

Spectral mean wave period obtained using the reciprocal integral moment of the wind waves spectrum. The wind waves spectrum is obtained by only considering the components of the two-dimensional wave spectrum that are under the influence of the local wind. The integration is performed to infinitely high frequencies.

mean_period_wind_waves:s

Examples

• https://api-mm.ncm.gov.sa/2025-07-17T00:00:00Z/mean_period_wind_waves:s/90,-180_-90,180:1000x600/html

Mean Wave Period

Spectral mean wave period obtained using the reciprocal frequency moment of the full wave spectrum. The integration is performed over all theoretical frequencies up to infinity. Again, the frequency wave spectrum is obtained by integrating the two-dimensional wave spectrum over all directions.

mean_wave_period:s

Examples

• Show a time series depicting the mean wave period. The queried location lies in the Philippine Sea south of Nagasaki.https://api-mm.ncm.gov.sa/2025-07-17T00:00:00ZP3D:PT1H/mean_wave_period:s/27.852903,130.116770/html

• A part of the corresponding csv-file.https://api-mm.ncm.gov.sa/2025-07-17T00:00:00ZP3D:PT1H/mean_wave_period:s/27.852903,130.116770/csv

  validdate;mean_wave_period:s
  2017-08-03T03:00:00Z;10
  2017-08-03T04:00:00Z;9.9
  2017-08-03T05:00:00Z;9.9
  2017-08-03T06:00:00Z;9.9
  2017-08-03T07:00:00Z;9.9
  2017-08-03T08:00:00Z;10
  2017-08-03T09:00:00Z;10.1
  2017-08-03T10:00:00Z;10.2
  2017-08-03T11:00:00Z;10.3

• https://api-mm.ncm.gov.sa/2025-07-17T00:00:00Z/mean_wave_period:s/90,-180_-90,180:1000x600/html