Surface wind speed distributions: Implications for climate and wind power

Surface constituent and energy fluxes, and wind power depend non-linearly on wind speed and are sensitive to the tails of the wind distribution. Until now, GCMs have not accounted for these effects at finer resolution than the gridscale (∼ 100 km). Using the best available global and regional scale wind speed measurements, at resolutions as fine as 25 km, we characterize the global ocean surface wind distribution and perform a series of studies of its implications for climate and wind power. First, significant improvements in predicted wind statistics and large-scale dynamics are realized when accounting for surface fluxes due to sub-gridscale GCM winds. Mean surface wind speed biases are reduced in part from the convex shape of the surface drag response to stronger winds. Second, we investigate the sensitivity of global ocean wind power to surface layer stability and revise current wind power estimates up by 50% globally with significant regional fluctuations owing to stability. Third, global ocean wind power is evaluated for multiple turbine characteristics including hub-height, usable portion of the wind speed distribution and siting depth. Only a fraction of potential wind power is extractable within regions of fast and variable winds. Using future technology, offshore turbines placed in waters no deeper than 200m could extract as much as 50% of onshore power. Together, these results demonstrate the importance of wind speed variability in understanding the coupled ocean-atmosphere climate system and energy potential for humankind