LAUSR

The 3-hourly gridded ERA-Interim climate reanalysis dataset, spanning 1979 to 2013, was used to investigate the spatial stationarity of the previously documented relationships between wind speeds and the NAO state in Europe. Over much of western Europe, wind speeds were found to be affected strongly by the concomitant states of the secondary and tertiary atmospheric teleconnections, namely the East Atlantic (EA) and the Scandinavian (SCA) patterns. These modify the geographic positions of the NAO dipole and modulate the influence of the NAO on wind statistics on regional scales, producing non-stationarities in the NAO-wind speed relationships. The interactions of these teleconnections play an important role in modifying wind speeds within Europe. Finally, systematic north-south changes in the Weibull distribution scale and shape parameters are documented along the western margin of Europe, as a function of different states of the NAO, the EA and the SCA. These effects influence both monthly averaged wind speeds and the statistical distributions of 3-hourly wind data, implying strong impacts on wind energy resources and expected wind power production. The results have implications for regional to continent-scale long-term planning of windfarm siting to minimise the impact of resource intermittency.