Large-scale atmospheric circulation forms and their impact on air temperature in Europe and northern Asia

Air temperature variations in Europe and northern Asia are strongly affected by atmospheric circulation. A large-scale study of temperature signals is presented, using a newly available global gridded daily temperature dataset. Major types of European Grosswetterlagen (large-scale weather patterns) and the Russian Vangengeim–Girs classification are compared in their spatial applicability to air temperatures within the past 110 years (1901–2010). The consistency of spatial patterns in the three most recent decades (1981–2010) is investigated, and temperature changes are interpreted against the backdrop of changes in character and frequency of circulation patterns. Both classifications largely explain the observed temperature variability. Spatial patterns are large-scale and strong in both regions, especially in winter. Both spatial extent and signal magnitude show a distinct seasonality with maximum values in winter and minimum ones in summer. Spatial patterns show little changes in Europe; yet the ability to explain temperature variability in northern Asia decreased within 1981–2010. European winter warming corresponds to increased maritime and to decreased continental air mass inflow, superimposed on the general warming trend. Northern Asian winter warming is partly explainable by circulation changes in January and February, but to a lesser extend in December. These results may be used to advance input variables of global climate models and to improve their performance in the European–Northern Asian area.