Trends in drought across Europe and their links to atmospheric circulation

We study trends in drought across the central latitude strip of Europe (defined as the region 47.5–52.5 °N and 2.5°W–32.5°E) during 1950–2019, and their links to atmospheric circulation. Drought characteristics are based on difference between potential evapotranspiration and precipitation in E–OBS data, and atmospheric circulation is characterized in terms of circulation types classified using daily sea level pressure patterns from the NCEP–NCAR reanalysis. Circulation types supporting drought in vegetation season (April–September) are identified, and we analyse changes in their occurrence since 1950, seasonal changes, and the connection with drought trends in individual European regions. We find that while in the early vegetation season, drought develops mainly in Central Europe, in the late vegetation season the most pronounced trends are shifted towards west. The circulation types supporting drought depend on regions and seasons, especially for directional types. The largest increase of the dry circulation types is observed in both seasons in Central Europe, and contributes to the pronounced drying.