Wave Height Parameters

Max Individual Wave Height | Significant Wave Height | Significant Height Total Swell | Significant Height Wind Waves

Maximum Individual Wave Height

From a theory of wave height distribution that includes non-linear effects, the estimation value of the largest single wave height in a record of 20 minutes is derived.

max_individual_wave_height:m

Examples

• Create a time series of the maximal individual wave height. The queried location lies to the south of Nagasaki in the Philippine Sea.https://api-mm.ncm.gov.sa/2025-07-17T00:00:00ZP3D:PT1H/max_individual_wave_height:m/27.852903,130.116770/html

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

Significant Wave Height

The significant wave height is traditionally defined as the mean wave height (trough to crest) of the highest third of the waves. Nowadays, it is usually defined as four times the standard deviation of the surface elevation or equivalently as four times the square root of the zeroth-order moment (area) of the full wave spectrum. ¹

significant_wave_height:m

Examples

• MetX chart showing the significant wave height along with the mean sea level pressure. Current situation:
  https://api-mm.ncm.gov.sa/2025-07-17Z/significant_wave_height:m/world:0.5,0.5/html_map
• Show a time series of the significant wave height. The queried location lies to the south of Nagasaki in the Philippine Sea.
  https://api-mm.ncm.gov.sa/2025-07-17T00:00:00ZP3D:PT1H/significant_wave_height:m/27.852903,130.116770/html

Significant Height Total Swell

Four times the square root of the integral over all directions and all frequencies 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.

significant_height_total_swell:m

Examples

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

Significant Height Wind Waves

4 times the square root of the integral over all directions and all frequencies of the windsea wave 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 (wind sea).

significant_height_wind_waves:m

Examples

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

1. Wikipedia Page of Significant Wave Height: http://en.wikipedia.org/wiki/Significant_wave_height
2. National Hurricane Center: https://www.nhc.noaa.gov/pdf/TAFB_wave_period.pdf