Twentieth century North Atlantic jet variability
Woollings, Tim; Czuchnicki, Camelia; Franzke, Christian. 2014 Twentieth century North Atlantic jet variability. Quarterly Journal of the Royal Meteorological Society, 140 (680). 783-791. 10.1002/qj.2197Before downloading, please read NORA policies.
Text (This article has been accepted for publication and will appear in a revised form in the Quarterly Journal of the Royal Meteorological Society, published by Wiley. Copyright Royal Meteorological Society. )
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Long records of the latitude and speed of the North Atlantic eddy-driven jet stream since 1871 are presented from the newly available Twentieth Century Reanalysis. These jet variations underlie the variability associated with patterns such as the North Atlantic Oscillation (NAO) and have considerable societal impact through variations in the prevailing westerly winds. While the NAO combines variations in the latitude and speed of the jet, these two characteristics are shown to have quite different seasonal cycles and interannual variability, suggesting that they may have different dynamical influences. In general, the features exhibited in shorter records are shown to be robust, for example the strong skewness of the NAO distribution. Related to this is a clear multimodality of the jet latitude distribution, which suggests the existence of preferred positions of the jet. Decadal variations in jet latitude are shown to correspond to changes in the occurrence of these preferred positions. However, it is the speed rather than the latitude of the jet that exhibits the strongest decadal variability, and in most seasons this is clearly distinct from a white-noise representation of the seasonal means. When viewed in this longer term context, the variations of recent decades do not appear unusual and recent values of jet latitude and speed are not unprecedented in the historical record.
|Item Type:||Publication - Article|
|Digital Object Identifier (DOI):||10.1002/qj.2197|
|Programmes:||BAS Programmes > Polar Science for Planet Earth (2009 - ) > Environmental Change and Evolution|
|Additional Keywords:||jet variability, NAO, reanalysis, climate noise, regime behaviour|
|Date made live:||01 Nov 2012 08:02|
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