Environmental Modeling Center Environmental Modeling Center Environmental Modeling Center United States Department of Commerce

WAVEWATCH III® Hindcast and Reanalysis Archives

MMAB currently maintains two classes of WAVEWATCH III® hindcasts.

  1. A thirty-year hindcast generated from the NCEP Climate Forecast System Reanalysis and Reforecast (CFSRR) homogeneous dataset of hourly high-resolution winds. The time period covers from 1979 through 2009. This is a true hindcast generated with a single version of the model and a statistically consistent forcing wind field, and is suitable for use in climate studies.
  2. An ongoing data set produced by rerunning the model from the operational wind fields to produce best-estimate nowcast datasets. This is a statistically inhomogeneous hindcast data set, because the underlying models are periodically updated. Therefore this data set should not be used for climate studies.

  3. Both are described in detail below, with links to the datasets, validation statistics from buoy match-ups, and visualizations of the model data fields.

    These hindcasts have been developed in stages, as part of a NOPP project to improve the physics packages of wind-wave models. In atmospheric modeling, a statistically homogeneous dataset can be generated by performing a reanalysis with consistent model setup and using all available data for the entire period. There is not enough data to develop a similar reanalysis for wind waves. However, wave dynamics are different from atmospheric dynamics, in the sense that they represent a forced/damped problem rather than an initial value problem, and wind forcing is the dominant process driving wave dynamics. Therefore it's possible to produce an accurate hindcast without assimilating wave data, but using a wind field from a long-term reanalysis such as the Climate Forecast System Reanalysis (CFSR, Saha et al 2010). This is a couple reanalysis of atmospheric, oceanic, sea-ice, and land data, at much higher resolution than previous reanalysis.

    Phase 1 (released in 2012)
    • Used the then-current operational WAVEWATCH III model (v3.14), with the Tolman and Chalikov (1996) source term package which was last tuned in 2000-2001.
    • Used wind forcing from CFSR (Saha et al, 2010)
    Phase 2 (released in 2017)
    • Used the WAVEWATCH III model (v5.08), with the Ardhuin et al (2010) source term package.
    • Used bias corrected CFSR winds.
    • Used an Arctic curvilinear grid.

    The production hindcast uses the operational multi-grid spectral wave model WAVEWATCH III® with operational NCEP winds and ice fields as input forcing fields. No wave data assimilation is performed. The model is run after the end of each month, with all available data.

    UPDATE: 23 July 2020
    EMC is in the midst of upgrading the major models, and the production hindcast has been temporarily suspended. We are looking into alternative ways to continue to produce this long-term dataset, but due to resource constraints do not expect this to proceed until further notice.