Impact of the uncertainty of reconstruction of climate changes in the last glacial cycle on modelling of ice sheets dynamics

Abstract

Ensemble (taking into account the uncertainty of climatic paleoreconstructions) numerical experiments were carried out with a model of ice sheet dynamics for the last glacial cycle (128 thousand years) in the Northern Hemisphere. The model, as a whole, adequately reproduces the spatial distribution of ice sheets and the height of their domes and corresponding ocean level changes. When perturbed with a sufficiently large amplitude of paleoclimatic data, the model reveals significant differences in the results of modeling the ice sheets from those obtained for the initial paleoreconstruction, including for the period of the last glacial maximum and for the time interval 58-51 thousand years ago (the initial part of MIS3). According to the experiments results, the uncertainty of global reconstructions for the last glacial cycle is 2°C, which is consistent with the available estimates.