Revisiting the evidence linking Arctic Amplification

Previous studies have suggested that Arctic Amplification has caused planetary-scale 3 waves to elongate meridionally and slowdown , resulting in more frequent blocking pat-4 terns and extreme weather. Here, trends in the meridional extent of atmospheric waves 5 over North America and the North Atlantic are investigated in three reanalyses, and it is 6 demonstrated that previously reported positive trends are an artifact of the methodology. 7 No significant decrease in planetary-scale wave phase speeds are found except in OND, 8 but this trend is sensitive to the analysis parameters. Moreover, the frequency of blocking 9 occurrence exhibits no significant increase in any season in any of the three reanalyses, 10 further supporting the lack of trends in wave speed and meridional extent. This work 11 highlights that observed trends in midlatitude weather patterns are complex and likely 12 not simply understood in terms of Arctic Amplification alone.