1. 28 August 2006Steinhausen meeting Hamburg On the integration of weather and climate prediction Lennart Bengtsson

2. 28 August 2006Steinhausen meeting Hamburg On the integration of weather and climate prediction What has been achieved in weather and climate modeling? What are probably now the most pressing issues? What is needed to achieve this? A strategy for climate prediction in Europe

3. 28 August 2006Steinhausen meeting Hamburg What has been achieved in weather modeling? Useful global prediction of synoptic scale weather for more than a week ahead Successful introduction of ensemble prediction Modest achievements in seasonal prediction of weather anomalies

4. 28 August 2006Steinhausen meeting Hamburg Improvements in NWP from Miyakoda (1972) to 2002. Courtesy ECMWF How long to get to D+10 in winter? 2006 at day 9

5. 28 August 2006Steinhausen meeting Hamburg St. Petersburg ensemble prediction 10.1 2006 17th onward ca -30 C

6. 28 August 2006Steinhausen meeting Hamburg What has been achieved in climate modeling? Realistic simulation of the general circulation of the atmosphere including many extreme features Major progress in simulating key aspects of the ocean circulation Progress in incorporating the interactions with the biosphere Demonstrating with relatively high probability that climate variations during the 20th century have been dominated by natural climate processes Demonstrating ( with high probability) that the climate trend of the 20th century cannot be explained without anthropogenic forcing Simulations of the climate of the 21st century with increasingly realistic models

7. 28 August 2006Steinhausen meeting Hamburg ECHAM5 simulated ERA40 determined from analyses. Köppen climate zones

8. 28 August 2006Steinhausen meeting Hamburg Coupled Model T63L31 Present climate Future climate

9. 28 August 2006Steinhausen meeting Hamburg Observes and simulated QBO Note the marked changes in wind direction at 10-20 hPa every 26-28 month

10. 28 August 2006Steinhausen meeting Hamburg 20 th Century (20C3M) 11/20 models have decadal signal PIcntrl (Control Runs) 10/20 models have decadal signal IPCC AR4 Arctic Temperature Anomalies by AOGCMs Courtesy, J Overland

11. 28 August 2006Steinhausen meeting Hamburg 50-year trends >0.23 corresponds to 95% significance T P Z 850 Sea ice

12. 28 August 2006Steinhausen meeting Hamburg Ten coldest European winters model and “observations” ( Luterbacher, 2005) ModelObs Model global anomaly Model height 500 hPa

13. 28 August 2006Steinhausen meeting Hamburg Pre-industrial temperatures in Europe (DJF) Model results ( smaller numbers in right column are observed values prior to 1950 covering ca 200 years Mean TSTD TMinMax De Bilt+4.3 +2.0 1.4 1.8 -1.0 -3.1 +7.6 +5.3 Hamburg+1.41.8-5.0+5.6 Hohenpeissenb.-1.6 -1.4 1.8 1.9 -6.9 -6.1 +2.2 +2,8 Paris+3.8 + 3.3 1.4 1.6 -0.8 -1.6 +6.8 +6.6 Oxford+5.1(L)1.2(L)+0.1+8.0 Moscow-10.62.6-19.7-2.0 Uppsala-2.5 -4.0 1.7 2.3 -8.0 -9.9 +1.8 +1.4 St. Petersburg-8.5 -7.2 2.2 2.6 -15.7 -14.6 -1.5 -1.1 Warsaw-3.3 -2.8 2.2 2.3 -11.7 -9.2 +2.3 +1.4 Vienna-2.3 -0.5 1.9 1.8 - 8.5 -5.8 +2.1 +3.3

14. 28 August 2006Steinhausen meeting Hamburg T213 Cyclones (>1x10 3 sec -1 ), 1960-1990. Simulation of hurricane trajectory during 30 years ECHAM5 model at T213 resolution Storms with 850 mb max. vorticity stronger than 10-3 s-1 Selected storm trajectory

15. 28 August 2006Steinhausen meeting Hamburg Intensity v Speed (T213)

16. 28 August 2006Steinhausen meeting Hamburg T213 Example Cyclone Intensity and SpeedMSLP T63 Vertical Structure

17. 28 August 2006Steinhausen meeting Hamburg T213 Regional Speed Distribution.

18. 28 August 2006Steinhausen meeting Hamburg Effect of resolution Comparing ECHAM5 T213 with T63 Max. Speed (m/sec) ) #/year

19. 28 August 2006Steinhausen meeting Hamburg Number of observed, ERA-40 analyzed and simulated by ECHAM5 (T159) hurricanes having a maximum wind speed higher than 33ms-1

20. 28 August 2006Steinhausen meeting Hamburg What are probably now the most pressing issues? To better clarify what is predictable and not predictable To better clarify the climate feedback processes To determine the regional climate change and its separation from natural climate variability To estimate risks of extreme events on different time scales

21. 28 August 2006Steinhausen meeting Hamburg Climate precdictability This will require models resolving high amplitude features This will require ensemble prediction to separate signal from noise This will require more advanced modeling and significantly increased computer resources

22. 28 August 2006Steinhausen meeting Hamburg Climate feedback processes The handling of clouds in models is the single most important issue This is likely to require higher resolutions as clouds are associated with weather systems at different scales This will require detailed validation and experimentation using best possible observed data. It will best be used to use the models in a forecasting mode

23. 28 August 2006Steinhausen meeting Hamburg Predicting risks of extreme events Significant harm to society is related to high frequency synoptic events ( hurricanes, extra-tropical storms) and to longer lasting anomalies such as heat waves and droughts Longer term risks include flooding in coastal areas related to sea level rise Global type risks (probably longer term), melting of Greenland ice, West Antarctica, major changes in ocean circulation

24. 28 August 2006Steinhausen meeting Hamburg A strategy for climate prediction in Europe There is a need for regular climate prediction to support environmental policies Europe has in climate and environmental policy more or less common interests and objectives In order to keep and enhance credibility in modeling this could best be achieved by a European agency with long term commitments of an operational nature Required resources in man power and computers can hardly be found on a national level in the longer term

25. 28 August 2006Steinhausen meeting Hamburg A strategy for climate prediction in Europe A joint European climate modeling and prediction initiative could be set up as an integrated part of ECMWF but with a research program organized in a different way Most of the research could best be done within national research units as now but with the difference that the work is done within a common framework A changed convention for ECMWF is presently being approved by the national governments and is expected to come into force in 2007 The new ECMWF convention will make it possible to set up a climate prediction program

26. 28 August 2006Steinhausen meeting Hamburg END