Reconstruction of Climate of the Eemian Interglacial Using an Earth System Model.
Part 1. Set-up of Numerical Experiments and Model Fields of Surface Air Temperature and Precipitation Sums

O. O. Rybak, E. M. Volodin, and P. A. Morozova

The paper analyzes the results of the numerical experiment aiming at the reconstruction of climate of the penultimate (Eemian) interglacial (last interglacial, LIG) obtained using the Earth system model developed in the Institute of Numerical Mathematics of RAS. Orbital parameters were set with the periodicity of one thousand years and were further interpolated with the time step of 100 years. Assuming that during the LIG the concentrations of greenhouse gases were not very much different from the preindustrial values, this potential forcing was neglected. The climatic block of the ESM was called every 100 model years to follow changes in orbital forcing. The sub-models of ice sheets were asynchronously coupled to the sub-models of the atmosphere and the ocean with the ratio of model years as 100 to 1. Obtained anomaly (Eemian versus preindustrial) fields of surface air temperature generally correspond to the results of the earlier studies. Changes in the structure of the global atmospheric circulation resulted in the transformation of the precipitation field in some world regions. In particular, precipitation growth in North Africa was the reason for the radical change of landscapes.