This experiment is the second part of an IPCC AR4 simulation (experiment ID a42) with the coupled climate model ECHO-G. The first part is a "climate of the 20th Century experiment (20C3M)". This second part, named Commit, is a "committed climate change experiment", a continuation run with greenhouse gases (GHGs) and aerosols fixed at their value in year 2000 and with a solar constant of 1365 W/m^2. This run (run1) is one member of a five-member ensemble simulation (run1 to run5), where each Commit member (experiment ID = a42-a46; period = 2001-2100) has been initialized with the model state at the end of the respective 20C3M member (ID = a42-a46; period = 1860-2000). Initial data for the 20C3M simulations were obtained by spinning up ECHO-G for six years with ocean restart files of a preindustrial simulation performed at the Freie Universitaet Berlin (FUB). The preindustrial runs were initialized with the Levitus climatology. Anthropogenic GHGs, sulfate aerosol direct and first indirect effects, and natural forcing (solar irradiance and volcanic activity implemented through varying solar constant) are used for the 20C3M simulations.
[1] DOIFeichter, J.; Lohmann, U.; Schult, I. (1997). The atmospheric sulfur cycle in ECHAM-4 and its impact on the shortwave radiation. doi:10.1007/s003820050163