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Triple Isotopic Composition of Oxygen in Polar Ice Core to understand the links between climate change and water cycle

Objective

Strong modifications of the water cycle favoured the major climate changes. Over the late Quaternary, the measurements of three water isotopes (H216O, HDO, H218O) in deep Antarctic and Greenland ice cores suggested a strong relationship between climate and water cycle over the succession of glacial and interglacial period and over the rapid climatic variability of the last glacial period.

Such a result comes from the different mass-dependent fractionation processes (equilibrium and kinetic) in the water cycle. However, even if a huge measurements and isotopic modelling efforts was produced, no quantitative reconstruction of past changes of water cycle could be proposed (especially changes in temperature and humidity of evaporative regions). It therefore prevents correct description of water cycle in global model to describe climate change mechanism.

The last water isotope, H217O, as additional ice core tracer, should provide the missing information because of different equilibrium and kinetic fractionation coefficients (as shown by preliminar measurements and simple modelling studies). Its difficult analytical measurement with sufficient precision for that purpose is now possible at the Institute of Earth Sciences in Jerusalem.

After a first calibration part with laboratory experiment and existing sampling over polar transects, we propose to measure H217O in deep ice cores in Antarctica and Greenland where H218O and HD16O are available to understand quantitatively the links between climate and water cycle variations. The use of simple and GCM models including water isotopes will favour the interpretation.

My knowledge of isotopes in ice cores and of the European ice cores community, the unique expertise of the Institute of Earth Sciences in H217O measurements and the collaboration with Laboratoire des Sciences du Climat et de l'Environnement for isotopic modelling are great advantages for the success of the project.

Call for proposal

FP6-2004-MOBILITY-5
See other projects for this call

Coordinator

THE HEBREW UNIVERSITY OF JERUSALEM
Address
The Authority For Research And Development, Edmond J. Safra Campus, Givat Ram
Jerusalem
Israel