Simulations of the response of the Miocene Antarctic ice sheet to CO2-driven climate variability

We present ice thickness and bedrock height from simulations of the Miocene Antarctic ice sheet (AIS), using the 3D thermodynamical Parallel Ice Sheet Model (PISM) version 0.7.3. The applied climate forcing consists of temperature and precipitation anomalies with respect to a preindustrial reference simulation, obtained from simulations using the atmosphere-ocean general circulation model COSMOS. These anomalies are added to an ERA-40/WOD-09 base climate. COSMOS was run using preindustrial settings, and Miocene settings with CO2 levels of 278 ppm (low), 450 ppm (medium), and 600 ppm (high). The steady state simulations using PISM are started with present-day bedrock conditions, with a present-day AIS (Bedmap2), and isostatically rebounded after removal of the ice. Additional simulations are started with the Wilson et al. (2012) late-Eocene bedrock topography reconstruction. The steady state simulations are conducted by applying the same climate forcing over 200 kyr. The transient simulations are performed by using an index method to interpolate between different forcing climate states. In these runs, the forcing climate state is gradually varied over quasi-orbital timescales of 400 kyr, 40 kyr, 1600 kyr, or 200 kyr. Details are given in the accompanying publication. For more information or data, please contact L.B. Stap mailto:lstap@awi.de. Dataset 2019_Stap_steadystate_startfrom_presentdayAIS.nc contains the data to plot Fig. 1. Dataset 2019_Stap_PISM_transient.xlsx contains the data to plot Fig. 2 and 3. Datasets 2019_Stap_steadystate_startfrom_noice.nc and 2019_Stap_steadystate_startfrom_Wilson_noice.nc contain additional data plotted in Fig. 2 and 3