The Global Climate Model currently used by EdGCM is a slightly modified version of the GISS GCM Model II first described and published by Hansen et al., 1983. This model was developed at the NASA Goddard Institute for Space Studies beginning in the late 1970's and was the primary GCM maintained and used by GISS scientists until the early 1990's. Model II parameterizations and control runs are described in Hansen et al., 1983 and the original NASA/GISS global warming simulations were performed using this model and published in Hansen et al. 1988 (abstract only available here). The 8 X 10 (latitude X longitude) version of this GCM is still in use as a research tool for paleoclimate and planetary studies, for very long simulations, or where limited computing resources are available. The EdGCM suite of software gives users the ability to create and conduct "Rediscovery Experiments"; simulations that reproduce many of the hundreds of experiments that have been conducted and published using this version of the NASA/GISS GCM.