Articles | Volume 4, issue 4
Geosci. Model Dev., 4, 1035–1049, 2011

Special issue: PlioMIP: experimental design, mid-Pliocene boundary conditions...

Geosci. Model Dev., 4, 1035–1049, 2011

Model experiment description paper 29 Nov 2011

Model experiment description paper | 29 Nov 2011

Simulating the mid-Pliocene climate with the MIROC general circulation model: experimental design and initial results

W.-L. Chan1, A. Abe-Ouchi1,2, and R. Ohgaito2 W.-L. Chan et al.
  • 1Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan
  • 2Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan

Abstract. Recently, PlioMIP (Pliocene Model Intercomparison Project) was established to assess the ability of various climate models to simulate the mid-Pliocene warm period (mPWP), 3.3–3.0 million years ago. We use MIROC4m, a fully coupled atmosphere-ocean general circulation model (AOGCM), and its atmospheric component alone to simulate the mPWP, utilizing up-to-date data sets designated in PlioMIP as boundary conditions and adhering to the protocols outlined. In this paper, a brief description of the model is given, followed by an explanation of the experimental design and implementation of the boundary conditions, such as topography and sea surface temperature. Initial results show increases of approximately 10°C in the zonal mean surface air temperature at high latitudes accompanied by a decrease in the equator-to-pole temperature gradient. Temperatures in the tropical regions increase more in the AOGCM. However, warming of the AOGCM sea surface in parts of the northern North Atlantic Ocean and Nordic Seas is less than that suggested by proxy data. An investigation of the model-data discrepancies and further model intercomparison studies can lead to a better understanding of the mid-Pliocene climate and of its role in assessing future climate change.