Climate Dynamics

, Volume 35, Issue 7–8, pp 1393–1409

Application of blocking diagnosis methods to General Circulation Models. Part II: model simulations

  • D. Barriopedro
  • R. García-Herrera
  • J. F. González-Rouco
  • R. M. Trigo


A previously defined automatic method is applied to reanalysis and present-day (1950–1989) forced simulations of the ECHO-G model in order to assess its performance in reproducing atmospheric blocking in the Northern Hemisphere. Unlike previous methodologies, critical parameters and thresholds to estimate blocking occurrence in the model are not calibrated with an observed reference, but objectively derived from the simulated climatology. The choice of model dependent parameters allows for an objective definition of blocking and corrects for some intrinsic model bias, the difference between model and observed thresholds providing a measure of systematic errors in the model. The model captures reasonably the main blocking features (location, amplitude, annual cycle and persistence) found in observations, but reveals a relative southward shift of Eurasian blocks and an overall underestimation of blocking activity, especially over the Euro-Atlantic sector. Blocking underestimation mostly arises from the model inability to generate long persistent blocks with the observed frequency. This error is mainly attributed to a bias in the basic state. The bias pattern consists of excessive zonal winds over the Euro-Atlantic sector and a southward shift at the exit zone of the jet stream extending into in the Eurasian continent, that are more prominent in cold and warm seasons and account for much of Euro-Atlantic and Eurasian blocking errors, respectively. It is shown that other widely used blocking indices or empirical observational thresholds may not give a proper account of the lack of realism in the model as compared with the proposed method. This suggests that in addition to blocking changes that could be ascribed to natural variability processes or climate change signals in the simulated climate, attention should be paid to significant departures in the diagnosis of phenomena that can also arise from an inappropriate adaptation of detection methods to the climate of the model.


Atmospheric blocking Automatic methods General Circulation Models ECHO-G model Climate change 


  1. Anderson JL (1993) The climatology of blocking in a numerical forecast model. J Clim 6:1041–1056CrossRefGoogle Scholar
  2. Austin JF (1980) The blocking of middle latitude westerly winds by planetary waves. Q J Roy Meteor Soc 106:327–350CrossRefGoogle Scholar
  3. Barriopedro D, Garcia-Herrera R, Lupo AR, Hernández E (2006) A climatology of Northern Hemisphere blocking. J Clim 19:1042–1063CrossRefGoogle Scholar
  4. Bengtsson LK, Hodges I, Roeckner E (2006) Storm tracks and climate change. J Clim 19:3518–3543CrossRefGoogle Scholar
  5. Chen WY, Juang HMH (1992) Effects of transient eddies on blocking flows: general circulation model experiments. Mon Wea Rev 120:787–801CrossRefGoogle Scholar
  6. Cohen J, Frei A, Rosen RD (2005) The role of boundary conditions in AMIP-2 simulations of the NAO. J Clim 18:973–981CrossRefGoogle Scholar
  7. Colucci SJ, Alberta TL (1996) Planetary-scale climatology of explosive cyclogenesis and blocking. Mon Wea Rev 124:2509–2520CrossRefGoogle Scholar
  8. Crowley T (2000) Causes of climate change over the past 1000 years. Science 289:270–277CrossRefGoogle Scholar
  9. D’Andrea F et al (1998) Northern Hemisphere atmospheric blocking as simulated by 15 atmospheric general circulation models in the period 1979–1988. Clim Dyn 14:385–407CrossRefGoogle Scholar
  10. Diao Y, Li J, Luo D (2006) A new blocking index and its application: blocking action in the northern hemisphere. J Clim 19:4819–4839CrossRefGoogle Scholar
  11. Doblas-Reyes FJ, Casado MJ, Pastor MA (2002) Sensitivity of the Northern Hemisphere blocking frequency to the detection index. J Geophys Res 107. doi:10.1029/2000JD000290
  12. Dole RM, Gordon ND (1983) Persistent anomalies of the extra-tropical northern hemisphere wintertime circulation: geographical distribution and regional persistence characteristics. Mon Wea Rev 111:1567–1586CrossRefGoogle Scholar
  13. Egger J (1978) Dynamics of blocking highs. J Atmos Sci 35:1788–1801CrossRefGoogle Scholar
  14. Ferranti L, Molteni F, Palmer TN (1994) Impact of localized tropical and extratropical SST anomalies in ensembles of seasonal GCM integrations. Q J Roy Met Soc 120:1613–1645CrossRefGoogle Scholar
  15. Fischer-Bruns I, von Storch V, González-Rouco JF, Zorita E (2005) A modelling study on the variability of global storm activity on timescales of decades and centuries. Clim Dyn 25:461–476CrossRefGoogle Scholar
  16. García-Herrera R, Barriopedro D (2006) Northern hemisphere snow cover and atmospheric blocking variability. J Geophys Res 111:D21104. doi:10.1029/2005JD006975 CrossRefGoogle Scholar
  17. González-Rouco JF, Beltarami H, Zorita E, Stevens MB (2009) Borehole climatology: a discussion based on contributions from climate modelling. Clim Past 5:97–127CrossRefGoogle Scholar
  18. Hoskins BJ, James IN, White GH (1983) The shape, propagation and mean-flow interaction of large scale weather systems. J Atmos Sci 40:1595–1612CrossRefGoogle Scholar
  19. Kaas E, Branstator G (1993) The relationship between a zonal index and blocking activity. J Atmos Sci 50:3061–3077CrossRefGoogle Scholar
  20. Kalnay E et al (1996) The NCEP/NCAR 40-years reanalyses project. Bull Amer Meteor Soc 77:437–471CrossRefGoogle Scholar
  21. Latif M et al (2001) ENSIP: the El Niño simulation intercomparison project. Clim Dyn 18:255–276CrossRefGoogle Scholar
  22. Legutke S, Voss R (1999) The Hamburg atmosphere–ocean coupled circulation model ECHOG, Tech. Rep. 18, DKRZ, Hamburg, Germany, pp 62Google Scholar
  23. Lejenäs H, Madden RA (1992) Traveling planetary-scale waves and blocking. Mon Wea Rev 120:2821–2830CrossRefGoogle Scholar
  24. Lejenäs H, Økland H (1983) Characteristics of northern hemisphere blocking as determined from long time series of observational data. Tellus 35A:350–362CrossRefGoogle Scholar
  25. Lucarini V, Calmanti S, Dell’Aquila A, Ruti PM, Speranza A (2007) Intercomparison of the northern hemisphere winter mid-latitude atmospheric variability of the IPCC models. Clim Dyn 28:829–848CrossRefGoogle Scholar
  26. Lupo AR (1997) A diagnosis of two blocking events that occurred simultaneously over the mid-latitude Northern Hemisphere. Mon Wea Rev 125:1801–1823CrossRefGoogle Scholar
  27. Lupo AR, Smith PJ (1998) The interactions between a midlatitude blocking anticyclone and synoptic-scale cyclones that occurred during the summer season. Mon Wea Rev 126:502–515CrossRefGoogle Scholar
  28. Miyakoda K, Sirutis J (1990) Subgrid scale physics in 1-month forecasts, II, Systematic error and blocking forecasts. Mon Wea Rev 118:1065–1081CrossRefGoogle Scholar
  29. Mullen SL (1994) The impact of an envelope orography on low-frequency variability and blocking in a low-resolution general circulation model. J Atmos Sci 7:1815–1825Google Scholar
  30. Nakamura H, Nakamura M, Anderson JL (1997) The role of high and low frequency dynamics and blocking formation. Mon Wea Rev 125:2074–2093CrossRefGoogle Scholar
  31. Nigam S, Lindzen RS (1989) The sensitivity of stationary waves to variations in the basic state zonal fow. J Atmos Sci 46:1746–1768CrossRefGoogle Scholar
  32. Nutter PA, Mullen SL, Baumhefner DP (1998) The impact of initial condition uncertainty on numerical simulations of blocking. Mon Wea Rev 126:2482–2502CrossRefGoogle Scholar
  33. Pelly J, Hoskins B (2003a) How well does the ECMWF Ensemble Prediction System predict blocking? Q J Roy Meteor Soc 129:1683–1702CrossRefGoogle Scholar
  34. Pelly J, Hoskins B (2003b) A new perspective on blocking. J Atmos Sci 60:743–755CrossRefGoogle Scholar
  35. Raible CC, Yoshimori M, Stocker TF, Casty C (2007) Extreme midlatitude cyclones and their implications for precipitation and wind speed extremes in simulations of the Maunder Minimum versus present day conditions. Clim Dyn 28:409–423CrossRefGoogle Scholar
  36. Randall DA et al (2007) Climate models and their evaluation. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007: the physical science basis. Contribution of working group I to the fourth assessment report of the intergovernmental panel on climate change. Cambridge University Press, CambridgeGoogle Scholar
  37. Roeckner E et al (1996) The atmospheric general circulation model ECHAM-4: model description and simulation of present-day climate. Report No. 218, Max Planck Institute for Meteorology, Hamburg, Germany, pp 90Google Scholar
  38. Sausen R, König W, Sielmann F (1995) Analysis of blocking events observation and ECHAM model simulations. Tellus 47A:421–438Google Scholar
  39. Shutts GJ (1983) The propagation of eddies in diffluent jet streams: eddy forcing of “blocking” flow fields. Q J Roy Meteor Soc 109:737–762Google Scholar
  40. Swanson J (2002) Dynamical aspects of extratropical tropospheric low-frequency variability. J Clim 15:2145–2162CrossRefGoogle Scholar
  41. Terray L, Valcke S, Piacentini A (1998) The OASIS coupler user guide, version 2.2. Technical report 253, TR/CMGC/98-05. CERFACSGoogle Scholar
  42. Tibaldi S, Molteni F (1990) On the operational predictability of blocking. Tellus 42A:343–365Google Scholar
  43. Tibaldi S, Tosi E, Navarra A, Pedulli L (1994) Northern and Southern hemisphere seasonal variability of blocking frequency and predictability. Mon Wea Rev 122:1971–2003CrossRefGoogle Scholar
  44. Tibaldi S, D’Andrea F, Tosi E, Roeckner E (1997) Climatology of Northern Hemisphere blocking in the ECHAM model. Clim Dyn 13:649–666CrossRefGoogle Scholar
  45. Tyrlis R, Hoskins BJ (2008) The morphology of Northern Hemisphere blocking. J Atmos Sci 65:1653–1665CrossRefGoogle Scholar
  46. Ulbrich U, Leckebusch GC, Pinto JG (2009) Extra-tropical cyclones in the present and future climate: a review. Theor Appl Climatol. doi:10.1007/s00704-008-0083-8
  47. Walsh KJE, Fiorino M, Landsea CW, McInnes KL (2007) Objectively determined resolution-dependent threshold criteria for the detection of tropical cyclones in climate models and reanalyses. J Clim 20:2307–2314CrossRefGoogle Scholar
  48. Watson JS, Colucci SJ (2002) Evaluation of ensemble predictions of blocking in the NCEP global spectral model. Mon Wea Rev 130:3008–3021CrossRefGoogle Scholar
  49. Wolff JO, Maier-Reimer E, Legutke S (1997) The Hamburg ocean primitive equation model. Technical report No. 13, German Climate Computer Center (DKRZ), Hamburg, Germany, pp 98Google Scholar
  50. Woollings T, Hoskins B (2008) Simultaneous Atlantic–Pacific blocking and the Northern Annular Mode. Q J Roy Meteor Soc 134:1635–1646CrossRefGoogle Scholar
  51. Zorita E, González-Rouco JF, Legutke S (2003) Testing the Mann et al. (1998) approach to paleoclimate reconstructions in the context of a 1000-yr control simulation with the ECHO-G coupled climate model. J Clim 16:1378–1390CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • D. Barriopedro
    • 1
  • R. García-Herrera
    • 2
  • J. F. González-Rouco
    • 2
  • R. M. Trigo
    • 1
  1. 1.CGUL-IDL, Faculdade de CiênciasUniversidade de LisboaLisbonPortugal
  2. 2.Departamento de Física de la Tierra II, Facultad de C.C. FísicasUniversidad Complutense de MadridMadridSpain

Personalised recommendations