The link between eddy-driven jet variability and weather regimes in the North Atlantic-European sector

Journal article

This study reconciles two perspectives on wintertime atmospheric variability in the North Atlantic-European sector: the zonal-mean framework comprising three preferred locations of the eddy-driven jet (southern, central, northern), and the weather regime framework comprising four classical North Atlantic-European regimes (Atlantic ridge AR, zonal ZO, European/Scandinavian blocking BL, Greenland anticyclone GA). A k-means clustering algorithm is used to characterize the two-dimensional variability of the eddy-driven jet stream, defined by the lower tropospheric zonal wind in the ERA-Interim reanalysis. The first three clusters capture the central jet and northern jet, along with a new mixed jet configuration; a fourth cluster is needed to recover the southern jet. The mixed cluster represents a split or strongly tilted jet, neither of which is well described in the zonal-mean framework, and has a persistence of about one week, similar to the other clusters. Connections between the preferred jet locations and weather regimes are corroborated – southern to GA, central to ZO, and northern to AR. In addition, the new mixed cluster is found to be linked to European/Scandinavian blocking, whose relation to the eddy-driven jet was previously unclear.

Authors: Madonna, M; Li, C; Grams, C; Woollings, T

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Royal Meteorological Society
• Journal: Quarterly Journal of the Royal Meteorological Society
• Volume: 143
• Issue: 708
• Pages: 2960–2972
• Publication date: 2017-11-21
• Acceptance date: 2017-08-30
• DOI: 10.1002/qj.3155
• EISSN: 1477-870X
• ISSN: 0035-9009
• Keywords: NAO; North Atlantic atmospheric variability; weather regimes; blocking; eddy-driven jet