GIS data for offshore wind speed (meters/second) at a 90 meter height above surface level. The data is specified to Exclusive Economic Zones (EEZ). The wind resource is based on NOAA Blended Sea Winds and monthly wind speed at 30km resolution from 1987-2005, using a 0.11 wind shear to extrapolate 10m - 90m. Annual average greater than or equal to 10 months of data, no nulls.

The NOAA Blended Sea Winds dataset contains ocean surface vector winds and wind stresses gridded at 0.25 degrees. Multiple time resolutions are available: 6-hour, daily, and monthly. Wind speeds were generated from satellite observations; directions, from a combination of National Centers for Environmental Prediction (NCEP) Reanalysis and European Center for Medium-Range Weather Forecasts (ECMWF) data assimilation products.

Hub height is an important determinant of wind resource at a given location. Due to drag close to ground-level, wind speeds fall at lower altitudes. Over rough terrain, that drop can be precipitous, but there is substantial drag even over relatively smooth ocean surfaces. Wind speeds in the Blended Sea Winds database are at 10 m above ground level. To extrapolate them to 90m heights, a power-law wind-shear adjustment using a shear exponent of 0.11 was applied. The exponent value was chosen based on the guidance of Schwartz et al. (2010), who support its use for U.S. marine areas. The coarseness of the escalation assumption is regretful but necessary given this dataset.

There were some missing months in the dataset, especially at polar latitudes. For cells with at least 10 months of data, the 10-month average was considered as the annual average; for cells with fewer than 10 months of data, no resource was given. As those grid cells tended to be at extreme northern latitudes, and the missing months were generally in winter, it is assumed that the gaps are to be ice-caused and likely those sites are too icy for economic wind development.

For more up to date data please visit the "Wind Resource Database" link below.