Wind speeds over the North Atlantic and Europe have decadal changes but no significant trends

12.2.2021
Our recently published study shows that there are no significant trends in wind speeds over the North Atlantic and Europe during 1979-2018, and the annual and decadal variations are large. The wind speed changes are mainly explained by the positioning of the jet stream and storm tracks and the strength of the north-south oriented pressure gradient over the North Atlantic.

The study investigated 10-m winds on monthly scales during 1979-2018 in the North Atlantic and Europe region using ERA5 reanalysis. During the whole 40 year period, the strongest winds occurred over the sea and seasonally during winter time. No significant trends were found in mean and extreme wind speeds but the annual and decadal changes were large. For example, winters in the 1990s in Northern Europe were stormier than average whereas winters in the 1980s and 2010s were windier in Southern Europe. The decadal wind speed changes are mainly explained by the positioning of the jet stream and storm tracks and the strength of the north-south oriented pressure gradient over the North Atlantic. For example, in the 1990s, the jet stream and storm track were shifted northwards and extended further east reaching Northern-Eastern Europe. The analysis also showed a correlation between wind speeds in the North Atlantic and the North Atlantic Oscillation (NAO) index, which is a measure of the pressure difference between the north and south North Atlantic. Wind speed changes are, therefore, related to changes in atmospheric circulation. The study showed that we can obtain more, and broader, information about wind speed changes by investigating long-term variability rather than just analysing linear trends over the whole time period.

Reference:

Laurila, T.K., V.A. Sinclair, and H. Gregow, 2020: Climatology, variability and trends in near‐surface wind speeds over the North Atlantic and Europe during 1979–2018 based on ERA5. International Journal of Climatology, https://doi.org/10.1002/joc.6957.