EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Eight Hundred Years of North Atlantic Jet Stream Variability and its Influence on European Climate Extremes

Valerie Trouet1, Matthew Meko1, Lara Klippel2, Flurin Babst3,4, Jan Esper2, Paul Krusic5, Momchil Panayotov6, and Rob Wilson7
Valerie Trouet et al.
  • 1Laboratory of Tree-Ring Research, University of Arizona, Tucson, USA
  • 2Department of Geography, Johannes Gutenberg University, Mainz, Germany
  • 3W. Szafer Institute of Botany, Polish Academy of Sciences, Krakow, Poland
  • 4Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
  • 5Department of Geography, Cambridge University, Cambridge, UK
  • 6Dendrology Department, University of Forestry, Sofia, Bulgaria
  • 7School of Earth and Environmental Sciences, University of St Andrews, St Andrews, UK

A recent increase in mid-latitude extreme weather events has been linked to anomalies in the position, strength, and waviness of the Northern Hemisphere polar jet stream. The latitudinal position of the North Atlantic Jet (NAJ) in particular drives climatic extremes over Europe, by controlling the location of the Atlantic storm track and by influencing the occurrence and duration of atmospheric blocking. To put recent NAJ trends in a historical perspective and to investigate non-linear relationships between jet stream position, mid-latitude extreme weather events, and anthropogenic climate change, long-term records of NAJ variability are needed. Here, we combine two tree-ring based summer temperature reconstructions from Scotland and from the Balkan Peninsula to reconstruct inter-annual variability in the latitudinal position of the summer NAJ back to 1200 CE. We find that over the past centuries, a northward summer NAJ position has resulted in heatwaves in northwestern Europe, whereas a southward position has promoted wildfires in southeastern Europe and floods in northwestern Europe. The great famine of 1315-1317 in northwestern Europe, for instance, was associated with prolonged flooding and cold summers that resulted in failed grain harvest and were related to a southern NAJ position. We further find an unprecedented increase in NAJ anomalies since the 1960s, which supports more sinuous jet stream patterns and quasi-resonant amplification as potential dynamic pathways for Arctic warming to influence midlatitude weather.

How to cite: Trouet, V., Meko, M., Klippel, L., Babst, F., Esper, J., Krusic, P., Panayotov, M., and Wilson, R.: Eight Hundred Years of North Atlantic Jet Stream Variability and its Influence on European Climate Extremes, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12400,, 2020