EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

The climate in Antarctica during the Middle Eocene: a modelling perspective

Frederic Fluteau1, Delphine Tardif1, Guillaume Le Hir1, Yannick Donnadieu2, Pierre Sepulchre3, Jean-Baptiste Ladant4, Fernando Poblete5, and Guillaume Dupont-Nivet6,7
Frederic Fluteau et al.
  • 1Université de Paris, Institut de physique du globe de Paris, CNRS UMR7154, Paris, France (
  • 2Centre Européen de Recherche et d’Enseignement des Géosciences de l’Environnement (CEREGE), Aix en Provence, France (
  • 3LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France (
  • 4Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA (
  • 5Departamento de Geología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Chile ( )
  • 6Geosciences Rennes, Univ. Rennes, CNRS, 35042 Rennes, France (
  • 7Institute of Geosciences, Potsdam University, 14476 Potsdam, Germany

The Middle Eocene represents the last ice-free period of the Cenozoic. Vegetation proxy data (wood, leaves, palynomorphs) discovered in the Antarctica peninsula and neighbouring islands or hosted in sedimentary sequences deposited on the continental margin reveal the presence of paratropical rain forests which thrived along the Antarctica coast during the Early Eocene. During the Middle and Late Eocene these flora have been progressively replaced by temperate Nothofagus-dominated rainforests (Contreras et al., 2013). Jacques et al. (2012) proposed, using a physiognomic approach (CLAMP), that a warm temperate and wet climate (with a marked summer rainy season) prevails until the middle Eocene (43±2 Ma) on the tip of the Antarctica Peninsula.

            To better constrain the climate in Antarctica and understand processes governing the polar climate during the Middle Eocene, we performed a set of experiments using the IPCC-like Earth System Model (IPSL-CM5A2-VLR) forced with a Middle Eocene (~40 Ma) paleogeography reconstruction and a 4 times pre-industrial atmospheric CO2 level (1120ppm). To highlight the importance of the seasonality, we launched 6 orbital configurations exploring end-members situations. To complete the procedure, simulated sea surface temperatures and sea ice extents were then employed as boundary conditions to force the Atmospheric General circulation model LMDz6 (run at higher spatial resolution) coupled with a soil and vegetation model ORCHIDEE to simulate the corresponding vegetation over Antarctica. The 6 end-members Earth's orbital configuration allows exploring the full climatic spectrum which would have been recorded by proxy data. Simulated changes in atmospheric circulation will be discussed and the simulated climate and vegetation will be confronted to paleoclimatic indicators and vegetation data.

How to cite: Fluteau, F., Tardif, D., Le Hir, G., Donnadieu, Y., Sepulchre, P., Ladant, J.-B., Poblete, F., and Dupont-Nivet, G.: The climate in Antarctica during the Middle Eocene: a modelling perspective, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18748,, 2020

This abstract will not be presented.