Data covering the marine environment, including fisheries, coral reef  health, ocean chemistry, and coastal zones.

oceans-seas-coasts

Oceans, Seas, & Coasts

### Overview  
  
This dataset shows “significant wave height," a measure for wave height that closely corresponds to what a trained observer would consider to be the mean wave height. More precisely, it is the average of the highest one-third of waves (measured from trough to crest) that occur in a given period. This is measured because the larger waves are usually more significant than the smaller waves. For instance, the larger waves in a storm cause the most beach erosion, or can cause navigation problems for mariners.

  
  
The National Oceanic and Atmospheric Administration (NOAA)/National Weather Service (NWS)/National Centers for Environmental Protection (NCEP) generate operational ocean wave predictions four times a day, and include 9-, 6- and 3-hour hindcasts, forecasts of every hour from the initial time out to 120 hours, and then forecasts at 3-hour intervals out to 180 hours. All outputs are global in scope, with 30-arc minute spatial resolution.
  
  
### Methodology  
  
WAVEWATCH III is a community wave modeling framework that includes the latest scientific advancements in the field of wind-wave modeling and dynamics. The core of the framework consists of the WAVEWATCH III third-generation wave model, developed at the US National Centers for Environmental Prediction in the spirit of the WAM model. The current framework evolved from earlier WAVEWATCH I & II model packages, and differs from its predecessors in many important points such as governing equations, model structure, numerical methods and physical parameterizations.

  
  
The model considers the effects of a wide range of factors and dynamics. Inputs can include water temperature, water depth, oceanic currents, wind, and tides; the model itself also incorporates complex physical interactions, such as between water and the sea floor, between waves and other waves, and dissipation due to whitecapping, bottom friction, and surf-breaking, as well as dampening from mud or ice. The predictions presented here, such as significant wave height, use the wave model WAVEWATCH III® using operational NCEP products as input. The model is run four times a day: 00Z, 06Z, 12Z, and 18Z.

  
  
WAVEWATCH III solves the random phase spectral action density balance equation for wavenumber-direction spectra. The implicit assumption of this equation is that properties of the medium (water depth and current) as well as the wave field itself vary on time and space scales that are much larger than the variation scales of a single wave. The model includes options for shallow-water (surf zone) applications, as well as wetting and drying of grid points. Propagation of a wave spectrum can be solved using regular (rectilinear or curvilinear) and unstructured (triangular) grids, individually or combined into multi-grid mosaics. 

  
  
For the full documentation, please see the source [methodology](https://github.com/NOAA-EMC/WW3/wiki/Manual).  
  
### Additional Information  
  
Resource Watch shows only a subset of the dataset. Every model run includes forecasts (and hindcasts) for a large number of time periods in the following several days (and the preceding day). Furthermore, every model run generates results for many indicators: significant wave height, peak wave period, wind sea wave height and period, primary swell wave height and period, secondary swell wave height in period, as well as wind speed and direction. Please click on the “Learn More” button to find this data on the source website.  
  
### Visualizing the Data  
  
Our team reformatted this dataset before displaying it on Resource Watch. See the documentation on how Resource Watch processed the data on [Github](https://github.com/resource-watch/nrt-scripts/tree/master/ocn_002_wave_height).  
  
### Disclaimer  
  
Excerpts of this description page were taken from the source metadata.

Ocean Watch

Wave Height

March 22, 2021, 0000 UTC Significant Wave Height (m)

March 24, 2021, 0000 UTC Significant Wave Height (m)

March 23, 2021, 0000 UTC Significant Wave Height (m)

March 22, 2021, 1200 UTC Significant Wave Height (m)