Science Source

Recent enhanced high-summer North Atlantic Jet variability emerges from three-century context

States that a recent increase in mid-latitude extreme weather events has been linked to Northern Hemisphere polar jet stream anomalies
States that a long-term, historical perspective of jet stream variability is needed
Combines two tree-ring records from the British Isles and the northeastern Mediterranean to reconstruct variability in the latitudinal position of the high-summer North Atlantic Jet (NAJ) back to 1725 CE
Finds that northward NAJ anomalies have resulted in heatwaves and droughts in northwestern Europe and southward anomalies have promoted wildfires in southeastern Europe
Finds an unprecedented increase in NAJ variance since the 1960s, which co-occurs with enhanced late twentieth century variance in the Central and North Pacific Basin
Results suggest increased late twentieth century interannual meridional jet stream variability and support more sinuous jet stream patterns and quasi-resonant amplification as potential dynamic pathways for Arctic warming to influence mid-latitude weather