Equilibrium State of the Greenland Ice Sheet in the Earth System Model

Abstract

Currently, the Earth system models are widely used for studying present-day climate dynamics and for palaeoreconstructions. A full Earth system model should include dynamical ice sheet models of Greenland and Antarctica as subsystems. To couple the latters with the atmospheric and with the oceanic blocks, it is necessary to introduce a special procedure to sustain mutual data exchange between subsystems with different temporal and spatial scales. In this paper, we give a brief description of the blocks of the Earth system model developed in the Institute of Numerical Mathematics of RAS (INMCM). On the basis of the previous studies aimed at examination of sensitivity of the cryospheric block of the model to variations in the key model parameters, we carried out numerical experiments to prove stability of the model climate and to establish equilibration time of the Greenland ice sheet to the conventional pre-industrial climate. It was confirmed that our Earth System Model with the interactively and asynchronously coupled Greenland ice sheet model simulates stationary climate. Equilibration time of the Greenland ice sheet is nearly 20 thousand model years. It was demonstrated that the values of calculated surface mass balance and its components correspond to similar model results described in the literature.