Forcings and projections of past and future wind speed over the Czech Republic
|Year of publication
|Article in Periodical
|Magazine / Source
|MU Faculty or unit
|wind speed; climate forcings; circulation indices; attribution analysis; wind-speed projections; regional climate models; Czech Republic
|Monthly, seasonal and annual wind-speed series from 119 meteorological stations situated throughout the Czech Republic indicate decreasing and statistically significant trends in the 1961–2015 period. Attribution analysis, applying multiple linear regression, was used to identify wind-speed components related to natural and anthropogenic climate forcings and internally-induced climate variability. A significant link to wind speeds was detected for the North Atlantic Oscillation Index, as well as for the closely-related Central European Zonal Index, especially during the winter season. An influence from the East Atlantic/Western Russia Pattern was found during autumn and winter, especially in the eastern part of the Czech territory. A weaker, although still significant, relation to volcanic activity also emerged, but was found to be likely spurious due to its absence in free atmosphere wind over the Czech territory. Changes in the large-scale circulation did not seem to be primarily involved in long-term wind stilling, despite a formal correlation between the stilling and anthropogenic forcing. Distinct geographical variations in the regression-estimated links suggest profound influence from interactions between the local features of the measuring sites and large-scale climate-forming factors. A total of 11 Euro-CORDEX Regional Climate Model simulations for Representative Concentration Pathways RCP4.5 and RCP8.5 were used for projection of annual and seasonal mean daily wind speeds for the territory of the Czech Republic in the 1951–2100 period. Despite correction of the model biases for individual regional climate models, these simulations largely underestimated the magnitude of declining observational trends in 1981–2010, with only annual, winter and spring values sharing the same sign of trend for both RCPs. Linear trends in wind speeds calculated for 1981–2100 for both RCPs show a significant negative trend in summer, while significant positive trends in winter and spring wind speeds were recorded in RCP8.5.