Regional and global climate for the mid-Pliocene using CCSM4
and PlioMIP2 boundary conditions
Deepak Chandan and W. Richard Peltier
Department of Physics, University of Toronto, 60 St. George Street, Toronto, Ontario, M5S1A7
Received: 20 Feb 2017 – Accepted for review: 22 Feb 2017 – Discussion started: 24 Feb 2017
Abstract. The Pliocene Model Intercomparison Project, Phase 2 (PlioMIP2) is an international collaboration to simulate the climate of the mid-Pliocene interglacial, marine isotope stage KM5c (3.205 Mya), using a wide selection of climate models with the objective of understanding the nature of the warming that is known to have occurred during the broader mid-Pliocene warm period. PlioMIP2 builds upon the successes of PlioMIP by shifting focus onto a specific interglacial and by using a revised set of geographic and orbital boundary conditions. In this paper, we present the details of the mid-Pliocene simulations that we have performed with the Community Climate System Model version 4 (CCSM4), and the enhanced variant of the PlioMIP2 boundary conditions, and discuss the simulated climatology through comparisons to our control simulations, and to proxy reconstructions of the climate of the mid-Pliocene. With the new boundary conditions, the CCSM4 model simulates a mid-Pliocene which is more than twice as warm as that with the boundary conditions used for PlioMIP Phase 1. The warming is more enhanced near the high-latitudes which is where most of the changes to the boundary conditions have been made. The elevated warming in the high-latitudes leads to a better match of the simulated climatology to proxy based reconstructions than what was possible with the previous version of the boundary conditions.
Chandan, D. and Peltier, W. R.: Regional and global climate for the mid-Pliocene using CCSM4
and PlioMIP2 boundary conditions, Clim. Past Discuss., doi:10.5194/cp-2017-21, in review, 2017.