Centre de formation sur l’environnement et la société

Accueil > Recherche > Projets > ACTES : Abrupt Climatic changes in Terrestrial European Eolian (...)

2.1 Presentation

2009-2012. ANR blanc. Projet BLAN08-3_309053

CERES-ERTI : Denis-Didier Rousseau (PI), Adriana Sima (IR CNRS), Maxime Debret (IR CDD)

Partners :

LSCE, Gif-sur-Yvette : Christine Hatté, Caroline Gauthier, Masa Kageyama, Gilles Ramstein

LGP, Meudon : Pierre Antoine, Olivier Moine

IPGP, Paris : France Lagroix

ISTerre, Grenoble : Catherine Chauvel

PEPS, Lyon : Christophe Lecuyer

Atmospheric circulation accounts responsible for rapid distribution of heat and moisture across the earth and hence determines our weather and regional climate, today and in the past. While the atmosphere itself does not hold an archive for paleoclimate reconstruction, it left abundant traces as eolian deposits in the ice and in terrestrial and marine sediments. Records from eolian deposits consistently suggest that atmospheric dynamics was highly variable during isotope stages 2 and 3 of the last glacial cycle glacial resulting in extremely dusty intervals alternating with non-dusty intervals on timescales of millennia and shorter. In detail, however, records from different European regions, archives and proxies differ considerably, hence holding a wealth of detail information a lot of which is still to be extracted. It will be crucial to get hold of detailed reconstructions of atmospheric circulation in order to provide a useful contribution to the toolbox for climate change projection. The strong atmospheric variations during the last glacial interval provide good test cases for how well we understand atmospheric circulation on all levels of conceptual and numerical modeling. However, as a prerequisite this requires a good knowledge of the patterns of prevailing atmospheric paleocirculation on various regional scales, as well as timing of atmospheric variability relative to other parameters of climatic and environmental change. ACTES project intends to combine the evidence from eolian records from Europe and ice sheets, and of model simulations of past atmospheric circulation during particular abrupt climate changes, (Dansgaard-Oeschger and Heinrich events) to synthesize knowledge on past atmospheric dynamics, define the present limits of understanding and formulate follow-on questions for predictive simulations of future climatic conditions.