Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bussestrasse 24, 27570 Bremerhaven, Germany
Abstract. We use the three-dimensional Parallel Ice Sheet Model (PISM) to simulate Northern Hemisphere ice sheets evolution through the last glacial-interglacial cycle. The simulation is driven by the NGRIP δ18O index combined with climate forcing at two time slices, the Last Glacial Maximum (LGM) and present day (PD). In order to investigate the sensitivity of the ice sheets to the atmospheric forcing, atmospheric output from nine climate models from the Paleoclimate Modeling Intercomparison Project Phase III (PMIP3) are used to force the ice sheet model with the same set-up. The results show large diversity in simulated ice sheets between different models. By comparing the atmospheric forcing, we found that summer surface air temperature pattern resembles the ice sheet extent pattern at the LGM, which shows great sensitivity to summer surface air temperature. This implies that careful constrains on climate output is essential for simulating reliable glacial-interglacial Northern Hemisphere ice sheets. The ablation process is of vital importance for high-latitude Northern Hemisphere ice sheets. Besides, the absent nonlinear interactions between ice sheet and atmosphere and ocean, which have different signals regionally, also contribute to the mismatches between simulated ice sheets and geological evidences. Hence, we highlight the needs for coupling an ice sheet model to GCM to take into account these missing processes.
How to cite. Niu, L., Lohmann, G., Hinck, S., and Gowan, E. J.: Sensitivity of atmospheric forcing on Northern Hemisphere ice sheets during the last glacial-interglacial cycle using output from PMIP3, Clim. Past Discuss. [preprint], https://doi.org/10.5194/cp-2017-105, 2017.
Received: 24 Aug 2017 – Discussion started: 30 Aug 2017
The sensitivity of Northern Hemisphere ice sheets to atmospheric forcing during the last glacial-interglacial cycle is investigated by using output from PMIP3 models. The results show large diversity in simulated ice sheets between different models. We found that summer surface air temperature pattern resembles the ice sheet extent pattern at the LGM. This study implies careful constrains on climate output is essential for simulating reliable glacial-interglacial Northern Hemisphere ice sheets.
The sensitivity of Northern Hemisphere ice sheets to atmospheric forcing during the last...