Available Parameters

Marine Parameters

Below is an overview of all marine parameters:

Significant Wave Height | Peak Wave Period | Mean Direction Total Swell | Mean Wave Direction | Max Individual Wave Height |

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

Mean Wave Direction Second Swell | Mean Wave Direction Third Swell | Mean Wave Period | Mean Wave Period First Moment |

Mean Wave Period First Swell | Mean Wave Period Second Moment | Mean Wave Period Second Swell | Mean Wave Period Third Swell |

Significant Height Total Swell | Significant Height Wind Waves | Significant Wave Height First Swell | Significant Wave Height Second Swell |

Significant Wave Height Third Swell | Stokes Drift

Ocean Current | Water Temperature | Salinity

Bathymetry

Each parameter is explained in more detail below.

 

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 wave spectrum. 1

significant_wave_height:m

Examples

 

Peak Wave Period

The peak wave period is defined as the wave period associated with the most energetic waves in the total wave spectrum at a specific point. Wave regimes that are dominated by wind waves tend to have smaller peak wave periods, and regimes that are dominated by swell tend to have larger peak wave periods. 2

peak_wave_period:s

Examples

 

Mean Direction Total Swell

Spectral mean direction in degrees over all frequencies and direction 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. Please note that we are using the meteorological convention to define directions (Read more here).

mean_direction_total_swell:d

Examples

 

Mean Wave Direction

Spectral mean direction in degrees over all frequencies and direction of the two-dimensional wave spectrum. Please note that we are using the meteorological convention to define directions (Read more here).

mean_wave_direction:d

Examples

 

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

 

Mean Direction Wind Waves

Spectral mean direction over all frequencies and direction of the wind waves spectrum. The wind waves spectrum is obtained by only considering the components of the two-dimensional wave spectrum that are still under the influence of the local wind. Please note that we are using the meteorological convention to define directions (Read more here).

mean_direction_wind_waves:d

Examples

 

Mean Period Total Swell

Spectral mean wave period obtained using the reciprocal integral moment of the wind waves 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

 

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

 

Mean Wave Direction First Swell

Spectral mean wave direction computed using the first-most energetic partition of the swell spectrum The 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. Please note that we are using the meteorological convention to define directions (Read more here).

mean_wave_direction_first_swell:d

Examples

 

Mean Wave Direction Second Swell

Spectral mean wave direction computed using the second-most energetic partition of the swell spectrum The 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. Please note that we are using the meteorological convention to define directions (Read more here).

mean_wave_direction_second_swell:d

Examples

 

Mean Wave Direction Third Swell

Spectral mean wave direction computed using the third-most energetic partition of the swell spectrum. The 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. Please note that we are using the meteorological convention to define directions (Read more here).

mean_wave_direction_third_swell:d

Examples

 

Mean Wave Period

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

mean_wave_period:s

Examples

 

Mean Wave Period First Moment

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

mean_wave_period_first_moment:s

Examples

 

Mean Wave Period First Swell

Spectral mean wave period obtained using the first integral moment of the total swell frequency spectrum. The integration is performed over all theoretical frequencies up to infinity. The total swell frequency spectrum is obtained by integrating the two-dimensional wave spectrum over all directions for all wave components that are no longer under the influence of the local wind.

mean_wave_period_first_swell:s

Examples

 

Mean Wave Period Second Moment

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

mean_wave_period_second_moment:s

Examples

 

Mean Wave Period Second Swell

Spectral mean wave period obtained using the second integral moment of the total swell frequency spectrum. The integration is performed over all theoretical frequencies up to infinity. The total swell frequency spectrum is obtained by integrating the two-dimensional wave spectrum over all directions for all wave components that are not under the influence of the local wind.

mean_wave_period_second_swell:s

Examples

 

Mean Wave Period Third Swell

Mean wave period computed using the reciprocal frequency moment of the third most energetic partition of the swell spectrum. The 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_wave_period_third_swell:s

Examples

 

Significant Height Total Swell

4 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

 

Significant Wave Height Wind Waves

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

significant_height_wind_waves:m

Examples

 

Significant Wave Height First Swell

Significant wave height for the first most energetic partition of the swell spectrum (as determined by ECMWF), where the significant wave height is defined as 4 times the square root of the integral over all directions and all frequencies of the first partition of the swell spectrum. The 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_wave_height_first_swell:m

Examples

 

Significant Wave Height Second Swell

Significant wave height for the second most energetic partition of the swell spectrum (as determined by ECMWF), where the significant wave height is defined as 4 times the square root of the integral over all directions and all frequencies of the second partition of the swell spectrum. The 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_wave_height_second_swell:m

Examples

 

Significant Wave Height Third Swell

Significant wave height for the third most energetic partition of the swell spectrum (as determined by ECMWF), where the significant wave height is defined as 4 times the square root of the integral over all directions and all frequencies of the third partition of the swell spectrum. The 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_wave_height_third_swell:m

Examples

 

Stokes Drift

For a pure wave motion in fluid dynamics, the Stokes drift velocity is the average velocity of a specific fluid parcel as it travels with the fluid flow. For instance, a particle floating at the free surface of water waves experiences a net Stokes drift velocity in the direction of wave propagation. Along with effects such as Ekman drift and geostrophic currents, the Stokes drift is one of the most relevant processes in the transport of marine debris. Please note that we are using the meteorological convention to define directions (Read more here).

Speed and direction:

stokes_drift_speed:<speed_unit>
stokes_drift_dir:d

Components (u is positive for a west to east flow, v is positive for a south to north flow ):

u_stokes_drift:<speed_unit>
v_stokes_drift:<speed_unit>

Available speed units: ms, kmh, kn

Examples

Ocean Current

These parameters describe the velocity of the ocean currents. Please note that we are using the meteorological convention to define directions (Read more here).

Speed and direction (surface level):

ocean_current_speed:<speed_unit>
ocean_current_direction:d

Components (surface level, u is positive for a west to east flow, v is positive for a south to north flow):

ocean_current_u:<speed_unit>
ocean_current_v:<speed_unit>

Speed and direction (submarine levels):

ocean_current_speed_<level>:<speed_unit>
ocean_current_direction_<level>:d

Components (submarine levels, u is positive for a west to east flow, v is positive for a south to north flow):

ocean_current_u_<level>:<speed_unit>
ocean_current_v_<level>:<speed_unit>

Available levels: 2m, 4m, 6m, 8m, 10m, 12m, 15m, 20m, 50m, 100m 1000m (below mean sea level)

Available speed units: ms, kmh, kn

Example

Water speed in 10m depth on a straight line from New York to Lisbon

Water Temperature

The temperature of the water.

Surface temperature:

water_temperature:C

Example

A cross section of the temperature in the Atlantic at -30° longitude from 60° to -70 degrees latitude.

Salinity

The amount of salt within the water.

Surface salinity:

salinity:psu

Example

Bathymetry

The depth of the ocean for each point on earth.

Ocean depth:

ocean_depth:<unit>

Available units: m, km, ft

Example

Global ocean depth as an image:

Ocean depth through the north atlantic at latitude 50, from longitude -60 to 0:

 

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

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