Från storskaliga cirkulationsmått till ytextremer: Att länka europeiska vintertemperaturextremer till atmosfärsdynamik

The scientific community has developed numerous indices to capture large‐scale atmospheric circulation modes linked to surface extreme weather including jet‐stream metrics (speed, latitude, split/merged regimes), Rossby wave breaking, and blocking, but their relative importance remains unclear. We apply established algorithms to ERA5-reanalysis data from 1940 to 2024 to compute these three index classes and identify which one show the strongest association with wintertime temperature extremes across Europe. We find that cold spells are predominantly associated with high‐latitude blocking in the largest part of Europe, with Rossby wave breaking playing an important role for cold spells in southeastern Europe. Warm extremes display greater regional variability. Blocking is the dominant feature in northern and southern Europe, wave breaking in central and eastern Europe while different jet‐stream configurations are linked to warm extremes in western Europe and Iberia. We further find that merged, high‐speed jet often co-occur with blocking conditions over Greenland, whereas split and northerly‐shifted jets align most closely with North Atlantic wave‐breaking and blocking events over the North Atlantic.