Clima en España: Pasado, Presente y Futuro – Madrid, February 2009 Decoding Mediterranean climate variability using lake sediments Decoding Mediterranean climate variability using lake sediments Daniel Ariztegui Section of Earth and Environmental Sciences University of Geneva Switzerland Daniel Ariztegui Section of Earth and Environmental Sciences University of Geneva Switzerland

Clima en España: Pasado, Presente y Futuro – Madrid, February 2009 Decoding

Clima en España: Pasado, Presente y Futuro – Madrid, February 2009 A NATURALIST'S VOYAGE ROUND THE WORLD First Edition - May 1860

The Great Drought was very well described by Darwin …During this time so little rain fell, that the vegetation failed; the brooks were dried up, and the whole country assumed the appearance of a dusty high-road… …Very great numbers of birds, wild animals, cattle, and horses perished from the want of food and water… The smaller streams in the Pampas were paved with a breccias of bones… …What would be the opinion of a geologist, viewing such an enormous collection of bones, of all kinds of animals and of all ages, thus embedded in one thick earthy mass?... Clima en España: Pasado, Presente y Futuro – Madrid, February 2009

Decode : verb(trans.) convert (a coded message) into intelligible language Decode : verb(trans.) convert (a coded message) into intelligible language PROXY

modern atmospheric circulation North Atlantic

Climate The North Atlantic Oscillation (NAO) negative (-)positive (+) The NAO index is defined as the anomalous difference between the polar low and the subtropical high during the winter season (December through March) modern atmospheric circulation

Climate The North Atlantic Oscillation (NAO) The NAO index is defined as the anomalous difference between the polar low and the subtropical high during the winter season (December through March) modern atmospheric circulation (+) dry in the Mediterranean (-) moist air into the Mediterranean

The North Atlantic Oscillation (NAO) in the Mediterranean realm How far west can be tracked ? modern atmospheric circulation Was this modern climate feature active during glacial intervals?

modern atmospheric circulation Lake Albano North Atlantic

Lake Albano seismo-stratigraphy and core location after Chondrogianni et al., 2004 high-resolution window into the LGM

core correlation and chronology after Chondrogianni et al., 2004 Lake Albano high-resolution window into the LGM

Lake Albano high-resolution window into the LGM Lithology

after Chondrogianni et al., 2004 Lake Albano high-resolution window into the LGM

after Chondrogianni et al., 2004 North Atlantic Oscillation (NAO) Lake Albano high-resolution window into the LGM periodical changes in productivity/sedimentation during LGM

after Chondrogianni et al., 2004 Centennial-millennial changes four alternating cold and warm intervals between H1 and H2 Decadal-interdecadal changes moisture fluctuations associated with NAO and/or ENSO like mechanisms Lake Albano high-resolution window into the LGM

The North Atlantic Oscillation (NAO) in the Mediterranean realm atmospheric circulation How far west can be tracked ? Was this modern climate feature active during glacial intervals?

modern atmospheric circulation Lake Butrint North Atlantic

Lake Butrint high-resolution window into the last three centuries Lake Butrint Albania Greece Corfu Italy Mediterranean Sea

Lake Butrint high-resolution window into the last three centuries Corfu Albania Lake Butrint Ionian Sea 1 km

Lake Butrint high-resolution window into the last three centuries sedimentary cores reference core

Lake Butrint high-resolution window into the last three centuries B 00-2B 00-3 Excellent core to core correlation laminated facies homogeneous facies

Lake Butrint high-resolution window into the last three centuries Depth (cm) Magnetic susceptibility Cs-137 (mBq/g) Years AD Density (g/cm 3 ) 1741 Ariztegui et al., in review

Lake Butrint high-resolution window into the last three centuries 1 cm one year 1 µm 1 mm gray layer dark brown layer white layer Spring Autumn Summer Winter Pennate diatoms centric diatoms carbonate crystals allochthonous OM autochthonous OM star-shaped aragonite sediment cycle one year

Lake Butrint high-resolution window into the last three centuries Ariztegui et al., in reviewDepth (cm) TOC (%)  13 C (OM) (‰) Years AD 0 Oxygen Index (mgCO 2 g -1 TOC) C/N  15 N (OM) (‰)  15 N (OM) (‰) Hydrogen Index (mgHC g -1 TOC) Hydrogen Index (mgHC g -1 TOC)  18 O (carbonate) (‰)  13 C (carbonate) (‰)  13 C (carbonate) (‰) sedimentary organic matter authigenic carbonates

Lake Butrint high-resolution window into the last three centuries Depth (cm) µm aragonite low Mg calcite µm 0 Ariztegui et al., in review

Lake Butrint high-resolution window into the last three centuries number of lamina data analyzed raw data mobile mean thickness (cm) Climate Thickness of the gray lamina year 2000 year 1740

Lake Butrint high-resolution window into the last three centuries period (calendar years) Climate Spectral analyses spectral density 3.5 years = NAO

Lake Butrint high-resolution window into the last three centuries The land-sea interface influence of the NAO index increasing evaporation for the last part of the 20 century (positive index) but… anthropogenic impact trigger the most recent changes in salinity

The North Atlantic Oscillation (NAO) in the Mediterranean realm atmospheric circulation How far west can be tracked ? Was this modern climate feature active during glacial intervals? YES shifting temperature, wind directions and source of moisture The Ionian and Adriatic Sea

THANKS EU-Project PALICLAS Swiss National Science Foundation Albanian Geological Survey Université de Genève ETH Zürich Clima en España: Pasado, Presente y Futuro – Madrid, February 2009

Lake Butrint high-resolution window into the last three centuries