The response of high-impact blocking weather systems to climate change

Mid-latitude weather and climate are dominated by the jet streams and associated eastward-moving storm systems. Occasionally, however, these are blocked by persistent anticyclonic regimes known as blocking. Climate models generally predict a small decline in blocking frequency under anthropogenic cl...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Kennedy, Daniel, Parker, Tess, Woollings, Tim, Harvey, Ben, Shaffrey, Len
Format: Article in Journal/Newspaper
Language:English
Published: American Geophysical Union 2016
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Online Access:https://centaur.reading.ac.uk/66054/
https://centaur.reading.ac.uk/66054/13/Kennedy_et_al-2016-Geophysical_Research_Letters.pdf
https://centaur.reading.ac.uk/66054/1/Kennedy_et_al_Revised2.pdf
https://centaur.reading.ac.uk/66054/2/Kennedy_et_al_SuppInfo_Revised2.pdf
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Summary:Mid-latitude weather and climate are dominated by the jet streams and associated eastward-moving storm systems. Occasionally, however, these are blocked by persistent anticyclonic regimes known as blocking. Climate models generally predict a small decline in blocking frequency under anthropogenic climate change. However, confidence in these predictions is undermined by, among other things, a lack of understanding of the physical mechanisms underlying the change. Here we analyze blocking (mostly in the Euro-Atlantic sector) in a set of sensitivity experiments to determine the effect of different parts of the surface global warming pattern. We also analyze projected changes in the impacts of blocking such as temperature extremes. The results show that enhanced warming both in the tropics and over the Arctic act to strengthen the projected decline in blocking. The tropical changes are more important for the uncertainty in projected blocking changes, though the Arctic also affects the temperature anomalies during blocking.