Significant Wave Height, Period, and Direction
Distributions of significant wave height and direction are important for determining structural loads on turbine installations. Such information is available from buoy observations collected by NOAA’s National Buoy Data Center (NDBC)4 and from hindcasts of models such as WAVEWATCH III. In addition, WAVEWATCH III also produces credible directional wave spectra (the joint frequency distribution of wave amplitude with direction). Recent improvements to WAVEWATCH III have extended its performance to shallow water regions.
Tidal Elevations
Tidal elevations for wind turbine structures are important primarily for designing access and for identifying the parts of structures that will need to be specially protected from sea water corrosion. Coverage and accuracy of tidal data is sufficient for wind development purposes. A primary source for tidal and other water-level information is NOAA’s Center for Operational Oceanographic Products and Services5 .
Currents
Information about ocean currents is important to assess structural loading, potential for scour of the sea bed, and for design of access to offshore structures. The IEC standard allows for the application of standard current profiles to surface current information to obtain subsurface currents. Site-based current profiles can also be readily obtained through the use of acoustic Doppler current profilers (ADCPs). The National Oceanographic Data Center (NODC)6 acts as a central repository of many collections of ocean current information. Airborne eXpendable Current Profile current data are also available from selected Atlantic and Gulf of Mexico hurricanes from Hurricane Field Program campaigns executed by NOAA in partnership with the National Science Foundation, National Aeronautics and Space Administration, and the Office of Naval Research.