PaleoMex. Climat-Homme-Environnement

Transcription

1 PaleoMex Climat-Homme-Environnement Objectives :document the Mediterranean climate (trends, variability, abrupt changes, extremes) and the water balance of the basin over the Holocene - Evaluate impacts on the surface and deep circulation, on the continental t climate and their consequences on human societies. Information of past climate using data from two differents time-scales Historical climatology - high resolution documentary and proxy data over the past millenium Paleoclimatology data on longer time scales (10,000 years) Targets (LIA, MWP, RWP, 8200 ans, sapropèle 1, MHSL..) Based on combined data model approach to provide an integrated model of the evolution of human societies in response to climate change and their impacts (sea level, land use, ecosystems and their biodiversity ) Strongly multidisciplinary - large spectrum of expertise (OA, ST, SHS) : historians, archeologists, paleoclimatologists, paleoceanographers, statisticians, modelers,

2 Letter of Intent International workshop in spring The mechanisms of the Mediterranean climate Marine and continental hydrological cycles Extreme events, hazards and risks Coastal lines and sea-level changes A common chronology of Holocene changes Climate environment man interactions Impact on productivity and biodiversity of continental and marine ecosystems Greece 1. Hellenic Centre for Marine Research 2. University of Athens 3. University it of the Aegean Spain 1. University of Madrid Ricardo García Herrera, 2. Universitat de Barcelona Swizterland 1.University of Bern Oeschger Centre for Climate Change Research & NCCR Climate 2. University of Geneva, United Kingdom 1S 1.Southampton University i 2. School of Geography, Plymouth 3. University of Reading 4. University of East Anglia, Cimatic Research Unit 5. University of Leeds Italy 1.Universita Politecnica delle Marche 2. Padoue University Turkey Istanbul University Marocco Tanger University Tunisia Sfax university Germany GKSS - Inst Hydrophysics USA 1. Laboratory of Tree-Ring Research, Tucson 2. Cornell University 3. University of Massachusetts, 4. Yale University Egypt 1- Alexandria University 2- National Institute of Oceanography and Fisheries (NIOF)

3 The Historical Period in marine cores The Little Ice Age Little Ice Medieval Warm Roman Warm Age Period Dark Ages Period Tephras Age A.D. (years) Lund et al., Nature 2006

4 1er exemple de reconstruction haute résolution en Méditerranée ans d enregistrement avec une résol. temp. de 4 ans SSTs alcénones Les proxies Profondeur: 200m 2.5 mm - 4 ans de résolution temporelle Versteegh, G^3, 2007

5 The historical period on continents Historical documents and geomorphological indicators provide information on Rhone and Durance floods. We see that t the Little Ice Age was characterized by frequent floods

6 Historical periods: written documents and tree-ring analysis Le bassin méditerranéen, un secteur privilégié d archives paléoenvironnementales - environnements contrastés - des archives très sensibles au changement climatique oxygène 18 de la cellulose de cèdres de l'atlas : la résolution est annuelle (la datation est absolue) Année

7 The Holocene: data-model comparaison Mid Holocene (6ka BP): reconstruction of annual temperature from pollen data (deviations from present climate) (Davis and Brewer, 2003) Deviations from present climate Mid Holocene (6ka BP): simulation using IPSL climate model. The west east and south north gradients are in agreement with the data

8 Summer Palmer Drought Severity Index in the Mediterranean Basin Comparison of the smoothed reconstruction of summer PDSI (aridity index) with its simulation by the ECHO G all forcing model (red). The curves are averaged on the whole Mediterranean Basin.

9 The Mediterranean Sea provides a unique opportunity to investigate the socio- environmental interactions at different time and spatial scales. To investigate their complexity, the plurality of human responses and solutions in mitigating social vulnerability to climate variability and thus explore new modelling approaches. Microscale studies covering a wide range of climatic forcing and level of political and social decision making. QuickTime et un décompresseur TIFF (LZW) sont requis pour visionner cette image. QuickTime et un décompresseur TIFF (LZW) sont requis pour visionner cette image.

10 End of the 20ème century Beyond the Historical period Between 9000 et 7500 yrs BP

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12 In the field, coring at sea and on land to retrieved ice cores, lacustrines cores In the labs, Screen technics like XRF, RX, magnetic parameters, to heavier geochemical analyses Data managment and computer time and facilities,

13 Coring at sea Coring on land

14 Continental drilling and micropaleontological analyses O i t l f l i t One main tools for paleoenvironment investigations is lacustrine cores and determination of micro organisms present in the samples

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16 RX and XRF facilities N ti l i t t National instrument at EPOC, Bordeaux

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18 Geochemical analyses Molecular indicators, major and trace elements, O and C isotopes on bilcarbonates, speleothems, tree rings, tephrochronology