Winter 2010 in Europe: A cold extreme in a warming climate

[1] The winter of 2009/2010 was characterized by record persistence of the negative phase of the North-Atlantic Oscillation (NAO) which caused several severe cold spells over Northern and Western Europe. This somehow unusual winter with respect to the most recent ones arose concurrently with public debate on climate change, during and after the Copenhagen climate negotiations. We show however that the cold European temperature anomaly of winter 2010 was (i) not extreme relative to winters of the past six decades, and (ii) warmer than expected from its record-breaking seasonal circulation indices such as NAO or blocking frequency. Daily flow-analogues of winter 2010, taken in past winters, were associated with much colder temperatures. The winter 2010 thus provides a consistent picture of a regional cold event mitigated by long-term climate warming.

[1]  Franco Molteni,et al.  On the operational predictability of blocking , 1990 .

[2]  Arun Kumar,et al.  Unusual extremes in the negative phase of the Arctic Oscillation during 2009 , 2010 .

[3]  Jianping Huang,et al.  The relationship between the wintertime north Atlantic oscillation and blocking episodes in the north Atlantic , 2001 .

[4]  J. Hurrell.  Decadal Trends in the North Atlantic Oscillation: Regional Temperatures and Precipitation , 1995, Science.

[5]  R. Seager,et al.  Northern Hemisphere winter snow anomalies: ENSO, NAO and the winter of 2009/10 , 2010 .

[6]  T. Osborn.  Recent variations in the winter North Atlantic Oscillation , 2006 .

[7]  Hailong Liu,et al.  The record‐breaking cold temperatures during the winter of 2009/2010 in the Northern Hemisphere , 2010 .

[8]  B. Hurk,et al.  Circulation statistics and climate change in Central Europe: PRUDENCE simulations and observations , 2007 .

[9]  P. Jones,et al.  Long-Term Variability of Daily North Atlantic–European Pressure Patterns since 1850 Classified by Simulated Annealing Clustering , 2007 .

[10]  P. Jones,et al.  Extension to the North Atlantic oscillation using early instrumental pressure observations from Gibraltar and south‐west Iceland , 1997 .

[11]  R. Vautard,et al.  North-Atlantic SST amplified recent wintertime European land temperature extremes and trends , 2011 .

[12]  H. Loon,et al.  The Seesaw in Winter Temperatures between Greenland and Northern Europe. Part I: General Description , 1978 .

[13]  Russell S. Vose,et al.  Maximum and minimum temperature trends for the globe: An update through 2004 , 2005 .

[14]  R. Vautard,et al.  Control of recent European surface climate change by atmospheric flow , 2009 .

[15]  P. Yiou,et al.  Extreme climatic events and weather regimes over the North Atlantic: When and where? , 2004 .

[16]  Christophe Cassou,et al.  Intraseasonal interaction between the Madden–Julian Oscillation and the North Atlantic Oscillation , 2008, Nature.

[17]  H. Loon,et al.  The seesaw in winter temperatures between Greenland and Northern Europe. Part II: Some oceanic and atmospheric effects in middle and high latitudes , 1979 .

[18]  David B. Stephenson,et al.  Arctic Oscillation or North Atlantic Oscillation , 2001 .

[19]  R. Vautard,et al.  Weather Regimes: Recurrence and Quasi Stationarity , 1995 .

[20]  M. Junge,et al.  North Atlantic Oscillation response to transient greenhouse gas forcing and the impact on European winter climate: a CMIP2 multi-model assessment , 2006 .

[21]  W. Collins,et al.  The NCEP–NCAR 50-Year Reanalysis: Monthly Means CD-ROM and Documentation , 2001 .

[22]  J. Wallace,et al.  The Arctic oscillation signature in the wintertime geopotential height and temperature fields , 1998 .

[23]  R. Pierrehumbert,et al.  Dynamics of Weather Regimes: Quasi-Stationary Waves and Blocking. , 1982 .

[24]  Michael Ghil,et al.  Persistent Anomalies, Blocking and Variations in Atmospheric Predictability , 1985 .

[25]  J. G. Charney,et al.  THE DYNAMICS OF LONG WAVES IN A BAROCLINIC WESTERLY CURRENT , 1947 .

[26]  Anders Moberg,et al.  Daily dataset of 20th‐century surface air temperature and precipitation series for the European Climate Assessment , 2002 .

[27]  Robert Vautard,et al.  Multiple Weather Regimes over the North Atlantic: Analysis of Precursors and Successors , 1990 .

[28]  R. Vautard,et al.  Inconsistency between atmospheric dynamics and temperatures during the exceptional 2006/2007 fall/winter and recent warming in Europe , 2007 .