An international study in which several Spanish research centres have taken part shows that wind speed has been reinforced in recent years, with positive consequences for wind energy production after decades of decreasing speed (a phenomenon known as stilling). Variations in wind speed are associated with changes in atmospheric circulation on a planetary scale.
The study (A reversal in global terrestrial stilling and its implications for wind energy production) involved scientists from different international institutions, including the Centre for Research on Desertification (CIDE), a joint centre of the Spanish National Research Council (CSIC), the University of Valencia and the Generalitat Valenciana. It deals with changes in wind speed over continents on a planetary scale, with emphasis on the northern hemisphere, and has been based mainly on wind series obtained at meteorological stations around the world since the late 1970s.
The work, published in the journal Nature Climate Change, shows that after decades of decreasing wind speed – a phenomenon known as stilling – “the decrease on continental surfaces has been interrupted since 2010, detecting from then on a strengthening of winds on a planetary scale”, according to CSIC researcher César Azorín Molina, one of the authors of the study.
Several theories have tried to explain the stilling phenomenon, such as the role of braking exerted by the increase in the roughness of the terrain associated with a greater forest mass, urban growth and other changes in land use. However, the recent strengthening of winds revealed in this new study points to the hypothesis of the greater role played by “changes in large-scale atmospheric circulation patterns,” adds Azorín.
The strengthening of winds, which has been three times greater than the decrease observed from 1978 to 2010, has had very positive repercussions on the increase in wind energy potential in the United States, Europe and China, among other places, with the advantage that this entails: wind, as is well known, is a substitute source for the use of fossil fuels to curb CO2 emissions and limit global warming.
According to the coordinator of the study, Zhenzhong Zeng, from Princeton University (United States), “going deeper into the causes behind these changes in atmospheric circulation and winds represents a scientific challenge due to its socio-economic and environmental impacts. Furthermore, predicting in advance these climatic cycles of strengthening and weakening of winds is key to optimizing wind energy production in the future.