Pliocene Climates and the Pliocene Model Intercomparison Project
Mark A. Chandler, Columbia University, NASA/GISS, CCSR, New York, NY, United States, Alan M Haywood, University of Leeds, School of Earth and Environment, Leeds, United Kingdom, Dr. Harry J Dowsett, PhD, USGS, Baltimore, MD, United States, Aisling M Dolan, University of Leeds, Leeds, LS2, United Kingdom, David B Rowley, The University of Chicago, Department of the Geophysical Sciences, Chicago, IL, United States, Ayako Abe-Ouchi, University of Tokyo, Atmosphere and Ocean Research Institute, Bunkyo-ku, Japan, Bette L Otto-Bliesner, NSF National Center for Atmospheric Research, Boulder, United States, Dan John Lunt, University of Bristol, School of Geographical Sciences, Bristol, BS8, United Kingdom and Ulrich Salzmann, Northumbria University, Department of Geography, Newcastle-Upon-Tyne, United Kingdom
Contact First Author: Mark A. Chandler; mchandler1@gmail.com
Previously Published Material: Similar material will be presented by the same group of authors at the April 2015 EGU. Little overlap in participation is expected, thus the dual presentations.
English Abstract:
The mid-Pliocene Warm Period probably bears a closer resemblance to the CMIP5 RCP8.5 scenario than any other well-studied geologic interval (see Masson-Delmotte et al., 2013, Box 5.1). Marine and terrestrial data point to high-latitude temperature amplification, decreases in sea ice and land ice, higher sea levels, and poleward expansion of warm climate biomes. But uncertainty remains regarding how nearly representative mid-Pliocene regional climates and processes are of Earth’s future climate. The Mid-Pliocene CO2 level was 350-450 ppm, higher than pre-industrial, but far lower than projections for even the mid-21
st century. Yet sea level rise was probably much greater than will occur in the coming century. The IPCC 5
th assessment points to significant melting of Greenland and West Antarctic ice sheets, plus some ice loss from East Antarctica, during the Pliocene. This, along with other geologic evidence, yields
high confidence that sea level was above present, with 20 meters being an upper bound. An additional disparity between Pliocene and future climate simulations exists in the North Atlantic, where warming surpasses all other regions during the Pliocene but lags in RCP8.5. The next phase of model-model-data comparisons, designated PlioMIP-2, will attempt to address some of these uncertainties.
PlioMIP Phase 1 (2008-2014) resulted in the most complete analysis to date of Pliocene climate, including: detailed analyses of ocean circulation and monsoon behavior, an examination of large-scale global climate features and the ability of models to reproduce regional climates reconstructed from marine and terrestrial paleodata. We will highlight some of the PlioMIP-1 results before discussing the new PlioMIP-2 experiment design. PlioMIP-2 will incorporate significant updates to the paleogeographic boundary conditions, including a new land/sea mask, topography, bathymetry, and the Greenland and Antarctic ice-sheets. Within the PlioMIP-2 framework modelling groups will also have the option of using dynamic global vegetation models. Finally, the long-term partnership with the USGS Pliocene Research Interpretation and Synoptic Mapping Project (PRISM4), will give PlioMIP-2 participants access to an expanded, high-resolution data set of marine proxy records designed to aid data/model comparisons.
