Wednesday, August 21, 2013

New paper debunks claims that 'Arctic amplification' causes extreme weather

A new paper published in Geophysical Research Letters debunks claims that "Arctic amplification" is causing an increase of extreme weather in North America or the North Atlantic, finding such claims are "an artifact of the methodology" and not real. The paper finds no evidence of an increased frequency of jet stream blocking or a decrease of jet stream speed, a result corroborated by a recent paper finding no significant changes of the jet stream over the past 140 years. The paper debunks claims by climate alarmists such as Heidi Cullen that "Arctic amplification" is causing a "constipated jet stream" leading to increased extreme weather in North America.

Full draft of paper available here

Additional material on this paper from the warmists at the Capital Weather Gang

Revisiting the evidence linking Arctic Amplification to extreme weather in midlatitudes

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


  1. Post today by Dr. Roger Pielke Jr on Congressional testimony that there is no evidence of an increase of extreme weather

  2. Dr. Judith Curry weighs in on this paper


  4. Climate models don't predict an increase of jet stream blocking from climate change: