Increasing anticyclonic influence over Central Europe between 1836–2015

Climate change has various effects in different regions on Earth. The shift of global circulation patterns, most importantly changing cyclone tracks and strengthening blocking episodes have serious influence on the regional climate in the midlatitudes. In this study, a 180-year long historical dataset was used to track the change of the circulation patterns over Europe, since different weather types and precipitation can be associated with different synoptic situations. An automated cyclone/anticyclone detection method was applied on the mean-sea level pressure data from the Twentieth Century Reanalysis Project (NOAA). The European domain was split into the areas of low and high pressure systems, thus in each location we were able to investigate the distribution of cyclonic and anticyclonic effects. Clustering methods were used to study the long-term shift of pressure centers.

In the 1836–2015 period, largely increasing anticyclonic influence can be seen in the Mediterranean, underlining the increasing risk of droughts. In the European domain, anticyclonic clusters generally shifted towards the Mediterranean, while cyclone centers showed a northward shift and a weakening tendency. However, the temporal trend of shifts was not consistent over the long study period with multiple breakpoints over the 20^th century. The statistically significant increase of anticyclonic influence over the 180-year long period was between 5–10% for Central Europe and reached 10% in the Mediterranean. Increasing frequency of low-pressure systems was found in Northern Europe. Results coincide with the regional climate impacts reported in literature and highlight the importance of the investigation of changes in climate dynamics over this highly populated area.