The ARM Climate Research Facility Data Archive has published the Radiative Transfer Model Intercomparison Project (RTMIP) data set, compiled by Bill Collins. This data set compares the radiation models embedded in the Atmosphere-Ocean General Circulation Models used in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. These radiation models were compared to current line-by-line (LBL) radiation codes in clear-sky, gas-only mode. The primary goal was to determine differences in radiative forcing by well-mixed greenhouse gases using various combinations of those gases.
To learn more about RTMIP, go to the Archive at http://iop.archive.arm.gov/arm-iop/0special-data/RTMIP/.