clima en españa: pasado, presente y futuro – madrid, 11-13 february 2009 decoding mediterranean...
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Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009
Decoding Mediterranean climate variability
using lake sediments
Decoding Mediterranean climate variability
using lake sediments
Daniel Ariztegui
Section of Earth and Environmental SciencesUniversity of [email protected]
Daniel Ariztegui
Section of Earth and Environmental SciencesUniversity of [email protected]
Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009
Decoding
Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 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, 11-13 February 2009Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009
Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 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
ClimateThe 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)
www.ldeo.columbia.edu/NAO/
modern atmospheric circulation
ClimateThe 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)
www.ldeo.columbia.edu/NAO/
modern atmospheric circulation
1860 1880 1900 1920 1940 1960 1980 2000
(+) 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
MediterraneanSea
Lake Butrint high-resolution window into the last three centuries
Corfu
Albania
Lake Butrint
Ioni
an S
ea
1 km
Lake Butrint high-resolution window into the last three centuries
sedimentarycores
referencecore
Lake Butrint high-resolution window into the last three centuries
B 00-2 B 00-3
Excellent core to core correlation
• laminated facies
• homogeneous facies
Lake Butrint high-resolution window into the last three centuries
Depth (cm)
30
20
10
0
Magnetic susceptibility
0
60
120Cs-137(mBq/g)
19631986 1917 1872 18111794
Years AD
0 10 20 30 40 5060 70 80 90 100 110 120 130 140 150 160
1.6
1.4
1.2
1.0
Density (g/cm3)
1741
Ariztegui et al., in review
Lake Butrint high-resolution window into the last three centuries
1 cm
one
ye
ar
1 µm1 µm
1 mm 1 mmgr
ay
laye
rda
rk b
row
n la
yer
whi
te
laye
r
SpringSpring
AutumnAutumn
SummerSummer
WinterWinterPennate diatoms
centric diatoms
carbonate crystals
allochthonous OM
autochthonous OM
star-shaped aragonitesedi
men
t cy
cle
one
ye
ar
1905
1893
Lake Butrint high-resolution window into the last three centuries
Ariztegui et al., in reviewDepth (cm)
0
2
4TOC
(%)
19631986
-30 .0
- 24.0
- 26.0
- 28.0
13C(OM)
(‰)
1917 1872 1811 1794Years AD
0
Oxygen Index(mgCO2 g -1 TOC)
200
400
C/NC/N9
11
13
15N(OM)
(‰)
15N(OM)
(‰)4.0
6.0
2.0
1741
0
100 Hydrogen Index(mgHC g -1 TOC)
Hydrogen Index(mgHC g -1 TOC)
200
50
150
0
- 4.0
- 8.0
18O(carbonate)
(‰)
- 4.0
0
- 2.013C(carbonate)
(‰)
13C(carbonate)
(‰)
- 6.00 20 40 60 80 100 120 140 160
Lake Butrint high-resolution window into the last three centuries
Dep
th
(cm
)
10
20
30
40
50
2000
1917
1 µm
aragonitelow
Mg calcite
1943
1986
1947
1929
1913
1 µm
1 µm
0
Ariztegui et al., in review
Lake Butrint high-resolution window into the last three centuries
number of lamina
0
0.4
0.8data analyzedraw datamobile mean
thickness(cm)
20 40 60 80 100 120 140 160 180 200 220 240 2600- 0.4
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
100 2000
0.14
0.04
0.10
0.08
101 5
spectraldensity
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, 11-13 February 2009Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009
Lake Butrint high-resolution window into the last three centuries