Abstract

The mid-Pliocene Warm Period (mPWP, 3.264 to 3.025 Myr ago) has been extensively studied through the use of general circulation models (GCMs). Whilst the output from these simulations replicates closely many of the patterns of the climate of the interval indicated by proxy data, at northern high latitudes the reconstructed proxy data temperatures exceed the model temperatures by over 15ºC for some sites.

This data-model discrepancy highlights the importance of focusing on model representation of processes that strongly affect the northern high latitude climates, such as sea. Results are presented from simulations of the mPWP with the GCM HadCM3 focusing on the climatic effects of changes to the parameterisation of sea ice albedo, in isolation and in combination with orbital and atmospheric CO2 uncertainties.

Simulated Arctic sea ice outputs from eight different GCMs as part of the Pliocene Modelling Intercomparison Project (PlioMIP) are presented, to demonstrate model dependency on past Arctic sea ice simulation.