Jürg Luterbacher and collaborators Oeschger Centre for Climate Change Research and

1. Influence of the blended ship log book and station SLP data set on Mediterranean temperature & precipitation back to 1750June 23 2008 Jürg Luterbacher and collaborators Oeschger Centre for Climate Change Research and Institute of Geography University of Bern, Bern, SwitzerlandEmail: juerg@giub.unibe.ch

2. Outline • Introduction, why is the Mediterranean of importance? • CCA between the blended SLP data and Mediterranean winter climate 1750-2006 main patterns, trends and crossvalidation • Future scenarios • Conclusions

3. Network, Winter SLP 1817 after Tambora (April 1815) and Verification statistics L L H Very good quality Küttel et al. 2008

4. European Winter temperature and SLP anomalies 1817 - + Luterbacher et al. 2007; Fischer et al. 2007; Küttel et al. 2008

5. + - + Tambora (April 1815), produced the “year without a summer 1816” Luterbacher et al. 2007; Fischer et al. 2007; Küttel et al. 2008

6. Why is the Mediterranean of importance? • The area is a ‘Hot-Spot’ for which potential climate change impacts on the environment and other activity sectors are particularly pronounced • Local/regional feedbacks (e.g. soil moisture-precipitation feedback), changes in atmospheric circulation and modes of natural variability are of importance • Importance of hydrological cycle, winter precipitation is crucial Water resources & water quality Agriculture & environment Economics & social development & behaviour

7. Importance of winter precipitation compared tothe annual rainfall (in %) Xoplaki 2002

8. Data and Methods Independent reconstructions • Gridded temperature 1750-2006, Mediterranean land areas(Luterbacher et al. 2004, 1901-2006 Climatic Research Unit) • Gridded precipitation 1750-2006, Mediterranean land areas(Pauling et al. 2006, 1901-2006 Climatic Research Unit) • Gridded SLP 1750-2006, combined station pressure and CLIWOC/ICOADS data(Allan and Ansell, 2006; Küttel et al. 2008) Method • Canonical Correlation Analysis (CCA) selection of optimally correlated patterns between SLP and Mediterranean temperature & precipitation

9. CCA1(SLP – temperature/precipitation 1750-2006) dryer and warmer (North), wetter and cooler (South) + warm & dry cool & wet wetter and cooler (North), drier and warmer (South) Xoplaki et al. 2008, work in progress

10. CCA2(SLP – temperature/precipitation 1750-2006) _ dry and warm, pos NAOI warm & dry + wet and cool, neg NAOI Xoplaki et al. 2008

11. Mediterranean winter precipitation and temperature trends 1966-2006 Precipitation Temperature Overall drying trend Overall warming trend GISS/NASA

12. Cross-validation; importance of SLP to explain Winter precipitation and temperature variability1750-2006 Precipitation Temperature Good skill: northern parts and Iberia Good skill: northern and eastern parts Xoplaki et al. 2008

13. Impacts of recent climate change in the Mediterranean (deforestation, desertification, drought, fires …)

14. A1B-Scenario for Winter 2021-2050(with respect to 1961-1990) Sea Level Pressure + 2 hPa Temperature Precipitation + 1–2°C - 10–30% Giorgi and Lionello 2008

15. Conclusions • New dataset allows dynamical studies on the large scale influence on European climate back to AD 1750 • Crossvalidated results indicate good predictive skill in the north and west (precipitation) and north and east (temperature) • Recent dry and warm winter conditions over the entire Mediterranean are not unique in the context of the past 250 years Regional differences • Recent trend towards drier and wamer conditions seems to be exceptional • The combined influence of two atmospheric patterns (NAO, East Atlantic / Western Russia) account significantly for the recent drier and warmer trend • Scenarios indicate a trend towards more high pressure situations (similar patterns found through CCA) drier and warmer winter conditions  Implications on environment, economy and society

16. Thank you very much for your attention!