1. Ice Cores Very important paleoclimatic archives. Records of past atmospheric conditions. –Temperature –Humidity –Snow accumulation –Atmospheric composition –Volcanic activity –Tropospheric turbidity –Wind speed, wind direction –Atmospheric circulation

3. Ice Core drilling

8. Stable Isotopes-Concepts Name SymbolDefinition Atomic numberZ# protons (p + ) Neutron numberN# neutrons (n) Mass numberA# p + + n

9. Abundance of stable isotopes of water IsotopeZAAbundance (%) Atomic wt. (amu) H1199.9851.007825 D120.0152.014102 16 O81699.76215.994915 18 O8180.20017.999160 17 O*8170.03816.999131

11. Physical properties of water H 2 16 OH 2 18 O Density (g/cm 3 at 20°C )0.9971.1106 Melting point (°C at 760 torr)0.000.28 Boiling point (°C at 760 torr)100.00100.14 Vapor pressure (torr at 100°C)760.00758.07 Viscosity (centipoise at 20.2°C)1.0021.056

12. Isotope effect and fractionation Isotopes undergo the same chemical and physical reactions. The rate of these reactions, however, could be different (isotope effect), resulting in the partitioning of isotopes (fractionation).

13. Terminology  =1000(R sample /R standard – 1) where R=heavy isotope/lighter isotope  18 O= 1000( 18 R sample / 18 R standard – 1) where 18 R= 18 O/ 16 O  D= 1000( 2 R sample / 2 R standard – 1) where 2 R=D/H Standard is V-SMOW (Vienna-Standard Meteoric Ocean Water).  18 O V-SMOW =  D V-SMOW = 0‰

16. Temperature Altitude Distance from the source Latitude IAEA (2001). GNIP Maps and Animations.

17. IAEA (2001). GNIP Maps and Animations

20. Fricke and O’Neil, 1999

23. Edwards et al., 2004

24. d-excess Meteoric Water Line:  D=8*  18 O+10 d-excess under “normal” conditions d=  D-8*  18 O Increased relative humidity or lower sea-surface temperature (reduced evaporation rates) produces lower d-excess values.

26. Dating Ice Cores Radio-isotopes Ice layers Ice flow models Reference horizons

27. Volcanic markers provide additional time control

28. Seasonal variations can be detected with microparticles and glacio-chemical data

29. Antarctic Ice Cores

30. Vostok Ice Core

33. Epica Group, 2004

39. Greenland

42. MIS-5MIS-3MIS-1 MIS-4 Blunier and Brook, 2001, Science

50. Warmer/Wetter? Colder/Drier?

51. Range of  18 O values in the Kilimanjaro ice core