Project: Climate change at the end of a warm stage - DEKLIM-EEM is a joint project consisting out of 9 individual proposals. The project was financially supported by the German Ministry for Education and Research(BMBF) within the framework of the research programme DEKLIM (www.deklim.de). The purpose of the joint project is to reconstruct the climate of past interglacials and to contribute to the understanding of mechanism that are responsible for the transition to a cold stage. This project was coordinated by the Institute for Geosciences, University of Mainz. A description of all individual proposals can be found at: http://www.uni-mainz.de/FB/Geo/Geologie/sedi/index.html The datasets in the CERA database are the results of the project contributions of the Model and Data Group at the Max-Planck-Institute for Meteorology and the Institute for Meteorology at the FU Berlin. The coupled atmosphere-ocean general circulation model ECHO-G has been used to perform climate simulations of the Eemian interglacial (125,000 years before present) and the subsequent glacial inception (115,000 years before present) by adapting Earth s orbital parameters and greenhouse gas concentrations to conditions of these periods. A simulation of pre-industrial climate is available for comparison. Summary: The purpose of the project DEKLIM-EEM is to reconstruct past interglacials based on proxy data and to understand the processes that are responsible for climatic changes during these interglacials by applying climate models. The data represent monthly average value of a simulation of the preindustrial climate (PRI) at around 1800 yr AD. Boundary conditions are equivalent to the other simulations of the project, apart from the concentration of greenhouse gases and orbital parameters: Greenhouse gas concentrations are derived from vostok ice core data: 280 ppmV CO2, 0.70 ppmV CH4 and 265 ppbV N2O. CFCs are set to zero. Orbital parameters have been calculated with the routine of Berger (1978): Eccentricity: 0.0167; Obliquity: 23.44; Perihelion: 282.7 The simulation has been started with the Levitus ocean climatology. ECHO-G is used as climate model. It is a coupled atmosphere/ocean model (ECHAM4_T30 + HOPE-E_T42er). The simulation was run on a NEC-SX6 (hurrikan). Atmospheric data were originally stored by the model every 12 hours. Ocean data is stored every month. As the boundary conditions are not time dependent, the time access is arbitrary. Related experiments: - ECHOG_A16_LIG control run, last interglacial (Eemian, 125 kyrBP, DEKLIM-EEM project), started with Levitus climatology, monthly mean values - ECHOG_A40_LGI: control run, last glacial inception (End of the Eemian, 115 kyrBP, DEKLIM-EEM project), started with Levitus climatology, monthly mean values.