Journal cover Journal topic
Climate of the Past An interactive open-access journal of the European Geosciences Union
Clim. Past, 11, 1527-1551, 2015
https://doi.org/10.5194/cp-11-1527-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
19 Nov 2015
Quantifying molecular oxygen isotope variations during a Heinrich stadial
C. Reutenauer1, A. Landais2, T. Blunier1, C. Bréant2, M. Kageyama2, M.-N. Woillez2,a, C. Risi3, V. Mariotti2, and P. Braconnot2 1Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
2Institut Pierre Simon Laplace (IPSL), Laboratoire des Sciences de Climat et de l'Environnement (LSCE), UMR8212 (CEA-CNRS-UVSQ), CE Saclay, Orme des Merisiers, Bat. 701, 91191 Gif-sur-Yvette Cedex, France
3Laboratoire de Météorologie Dynamique UMR8539, IPSL/CNRS/UPMC, 4, place Jussieu, 75252 Paris Cedex 05, France
anow at: IFPEN, 14 avenue de Bois Préau, 92852 Rueil-Malmaison Cedex, France
Abstract. δ18O of atmospheric oxygen (δ18Oatm) undergoes millennial-scale variations during the last glacial period, and systematically increases during Heinrich stadials (HSs). Changes in δ18Oatm combine variations in biospheric and water cycle processes. The identification of the main driver of the millennial variability in δ18Oatm is thus not straightforward. Here, we quantify the response of δ18Oatm to such millennial events using a freshwater hosing simulation performed under glacial boundary conditions. Our global approach takes into account the latest estimates of isotope fractionation factor for respiratory and photosynthetic processes and make use of atmospheric water isotope and vegetation changes. Our modeling approach allows to reproduce the main observed features of a HS in terms of climatic conditions, vegetation distribution and δ18O of precipitation. We use it to decipher the relative importance of the different processes behind the observed changes in δ18Oatm. The results highlight the dominant role of hydrology on δ18Oatm and confirm that δ18Oatm can be seen as a global integrator of hydrological changes over vegetated areas.

Citation: Reutenauer, C., Landais, A., Blunier, T., Bréant, C., Kageyama, M., Woillez, M.-N., Risi, C., Mariotti, V., and Braconnot, P.: Quantifying molecular oxygen isotope variations during a Heinrich stadial, Clim. Past, 11, 1527-1551, https://doi.org/10.5194/cp-11-1527-2015, 2015.
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Short summary
Isotopes of atmospheric O2 undergo millennial-scale variations during the last glacial period, and systematically increase during Heinrich stadials. Such variations are mostly due to vegetation and water cycle processes. Our modeling approach reproduces the main observed features of Heinrich stadials in terms of climate, vegetation and rainfall. It highlights the strong role of hydrology on O2 isotopes, which can be seen as a global integrator of precipitation changes over vegetated areas.
Isotopes of atmospheric O2 undergo millennial-scale variations during the last glacial period,...
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