Antarctic ice cores : from Byrd to Vostok Past climate changes : general presentation and tools Antarctic ice cores : from Byrd to Vostok Greenland ice cores : from Camp Century to GRIP/GISP2 - Ongoing projects : North GRIP, EPICA and others

? GRIP and GISP 2 diverge below about 2720 m

NorthGRIP Project Denmark Belgium Iceland France Germany Japan Sweden Switzerland USA To appear in Nature, September 9

North GRIP Project : undisturbed Eemian (gas measurements)

North GRIP / GRIP difference appears modulated by the size of the ice sheet

Comparison of NorthGRIP with a North atlantic record

10 NATIONS: Belgium, Denmark, France, 10 NATIONS: Belgium, Denmark, France, Germany, Italy, Netherlands, Norway, Sweden, Switzerland, United Kingdom Two SITES : Dome C et DML. 5 CONSORTIA : Gas, Chemistry, Isotope, Physical properties, Dust.

KOHNEN G. Von Neumayer DOME C B.T.N. D.D.U.

1996/1997 : casing 130m 1999/2000 : casing 1997/1998 : 364m EDC99 1999/2000 : casing EDC96 1997/1998 : 364m 1998/1999 : 781m 2000/2001 : 1459m 2001/2002 : 2864m 2002/2003 : 3201m

What is the geographical significance of the Vostok temperature record ? Can we extend it further back in time ?

Comparison of five cores from the East Antarctic Plateau

EPICA Dome C provides more detailed information

2000 3000 Profondeur 1000 EPICA Dome C Note the change of pacing below 2800 m corresponding to MIS 12 (around 450 kyr BP)

information available (developed by F.Parennin) Dating obtained by an inverse method aimining to an optimal use of the chronological information available (developed by F.Parennin)

Correspondence between MIS 16.2 and the low deuterium value Change of pacing is also seen in the oceanic record (at least to a certain extent) Correspondence between MIS 16.2 and the low deuterium value

Comparison with the Devils Hole calcite record

Change of atmospheric composition during termination 5

The period around the transition towards 11 The period around the transition towards 11.3 resembles the last transition The first part of 11.3 is Holocene like (as far as the deuterium record is concerned)

What is the geographical significance of the Vostok temperature record at the glacial-interglacial timescale ? We can extend Vostok further back in time

Deep (more than 2 km long) ice cores in Antarctica

Comparison of Dome F and Vostok profiles Watanabe et al., Nature

Comparaison of Vostok and Dome Fuji isotopic profiles Watanabe, Jouzel, Johnsen, Parrenin, Shoji, Yoshida (Nature, 2003)

Comparison of the Dome F and Vostok temperature profiles

Comparison of the Dome F, Vostok and EPICA Dome C(800 kyr)

340,000-year Centennial-Scale Marine Record of K.Pahnke, R.Zahn, H.Elderfield, M.Schulz , Science, August, 2003 340,000-year Centennial-Scale Marine Record of Southern Hemisphere Climatic Oscillation (45°S, East of New Zealand)

EPICA Dome C and GRIP Millenial Variability

Comparison of Vostok, Dome F, EPICA Dome C and GRIP over the last 80 ka

Blunier and Brook, Science 2001

Raisbeck et al., Goldschmidt Conference, 2002 The 10Be peak straddles event 10, exactly as seen in the GRIP core. This implies that, within our ability to resolve, which we presently estimate as 200 years, the GRIP and EPICA climaterecords at this time are synchronous. Small events / Large events ? Interesting modelling approach of Johnsen and Stocker, Paleoceanography, 2003

Stocker and Johnsen ; Paléocéanography, 2003

East Antarctica : Deep ice core Characteristics H(m) A(g/cm2) Z (m age (ky) Vostok 3750 2 3310 420 Dome F 3090 2.7 2503 330 EPICA DC 3320 2.7 3190 800 EPICA DML 2760 6.4 2565 200 Dome B 3.5 780 30 Dome A The future of ice core research International Participation in Ice Core Sciences (IPICS) Workshop

International Partnership for Ice Core Science A project to recover the longest possible ice core paleoclimate record Jean Jouzel and Frédéric Parennin Some criteria - High ice thickness and low Accumulation : - A/H as low as possible : East Antarctica …. - Low horizontal speed (dome) - Some melting at the base ? Relatively flat bedrock - Well documented and accessible area - Need for more data and dedicated modeling Importance of drilling in coastal areas Greenland : getting back to the previous glacial Tropical and mid - latitude glaciers

as well as improved 3D ice flow modeling There is some possibility to get a more than 1 Myr undisturbed paleorecord but identiying a site will need to better document accumulation and other properties as well as improved 3D ice flow modeling

This was a pleasure for me to give these ISCS lectures Thanks for your attention