Climate variations in the eastern Mediterranean over the last millennium; New evidence from proxy reconstructions and high resolution climate models

Transcription

1 Climate variations in the eastern Mediterranean over the last millennium; New evidence from proxy reconstructions and high resolution climate models Elena Xoplaki, Jürg Luterbacher Juan José Gómez-Navarro, Eduardo Zorita, Johannes Werner, PAGES Euro-Med 2k Consortium Justus-Liebig University of Giessen

2 Outline The Mediterranean Basin Palaeodata availability some examples Multi-proxy summer temperature reconstruction Coupled MM5 ECHO-G RCM The last millennium Medieval Climate Anomaly, Little Ice Age Conclusions

3 The Mediterranean The sea, the orography, km coastline One eco-region: 10% of vegetation species, 7% of marine species 21 countries and the EU, Contracting Parties to the Barcelona Convention 430 Mio inhab., 7% world population, 13% world GDP, 33% international tourism

4 Palaeoscience and importance for global change research Palaeoscience : the study of climate and environmental processes in the recent past prior to the existence of instrumental records; The palaeorecord evidence in concert with modelling of past scenarios provides a quantitative understanding of past Earth System variability and the underlying processes; In order to better understand current global changes and to project future scenarios, knowledge of the past is imperative; The past does not provide a prescriptive guide to the future but can form the basis for an evaluation of present day trends, future probabilities and likely human consequences. IGBP- PAGES 2009

5 Simulated and reconstructed NH temperature changes Masson-Delmotte et al., 2013 IPCC AR5, WGI, Chapter 5

6 PAGES 2k initiative

7 Mediterranean climate proxies Sedimentary flood records Speleothems Corals Historical documents Marine cores Lacustrine cores Tree rings Varved sediments Bradley 1999

8 Distribution of speleothem-based climate reconstructions Luterbacher et al Speleothems are formed when calcium carbonate precipitates from degassing solutions seeping into limestone caves

9 Chronology of cold spells Baghdad, Iraq, ninth and tenth century The Arabic historians records chronologically narrate social, political and religious matters; some mention also ancient meteorological notes Dominguez-Castro et al. 2012

10 Luigi Mayer, R. Brown Historic Gallery, Pall Mall 1802 Nilometer Pharaonic and medieval Egypt depended solely on winter agriculture and hence on summer floods. The rise of the waters of the Nile was measured regularly from the earliest times. Compiled annual maxima and minima of the water level recorded at nilometers, back to the 7th century.

11 Tree rings Temperature Precipitation Luterbacher et al Pyrenees and Alpine sites reflect summer temperatures Sites in the south reflect hydroclimatic evidence (season dependent)

12 Mediterranean terrestrial and marine proxies covering at least 600 years Luterbacher et al length of the proxies varies proxies reflect different climate information (temperature, precipitation, sea level changes, ph, sea water temperature, water mass circulation, etc.) proxies may record climate conditions at different times of the year proxies have a different temporal resolution (from daily to multi-decadal)

13 The MM5 ECHO-G model

14 Regional model setup 45 km resolution domain implemented in the regional simulations Modified climate version of the MM5 (mesoscale meteorological model) Parametrizations chosen to reduce computational cost and retaining accurate skill Boundaries updated every 12 hours No spectral nudging Two domains of 135 and 45 km Gómez-Navarro et al. Clim. Past 2013

15 ECHO-G / OETZI2 external forcings OETZI2 Driven by ECHO-G: Atmospheric-Ocean Coupled General Circulation Model Spectral model (T30) Prescribed external forcings high uncertainty volcanic activity no volcanic forcing Hünicke et al. 2010

16 Medieval Climate Anomaly Summer OETZI2, Hünicke et al Data from Gómez-Navarro et al. Clim. Past 2013

17 MCA minus LIA Summer OETZI2, Hünicke et al Data from Gómez-Navarro et al. Clim. Past 2013

18 Data from Gómez-Navarro et al. Clim. Past 2013 Luterbacher et al. 2012

19 Data from Gómez-Navarro et al. Clim. Past 2013

20 Data from Gómez-Navarro et al. Clim. Past 2013

21 Data from Gómez-Navarro et al. Clim. Past 2013

22 Data from Gómez-Navarro et al. Clim. Past 2013

23 Data from Gómez-Navarro et al. Clim. Past 2013

24 Data from Gómez-Navarro et al. Clim. Past 2013

25 500hPa differences MCA minus LIA OETZI2, Hünicke et al. 2010

26 500hPa differences MCA minus LIA OETZI2, Hünicke et al. 2010

27 500hPa differences MCA minus LIA OETZI2, Hünicke et al. 2010

28 500hPa differences MCA minus LIA OETZI2, Hünicke et al. 2010

29 500hPa differences MCA minus LIA OETZI2, Hünicke et al. 2010

30 500hPa differences MCA minus LIA OETZI2, Hünicke et al. 2010

31 Conclusions Lack of annually resolved climate proxies in the area High temporal and spatial resolution summer temperature reconstruction The recent summer temperatures seem not to be unprecedented in the context of the last millennium High resolution RCM allows for accurate spatial structure of climate variability, in a complex terrain

32 Conclusions RCM strong warming in the 20th century connected with the lack of net cooling by tropospheric aerosols MCA variable in time; relatively warm and wetter over the Eastern Mediterranean Qualitative information agree with models on precipitation

33

34 Thank you very much for your attention!