This is monthly ocean forcing data, 1860-2000, run #5, from the NOAA Geophysical Fluid Dynamics Laboratory's (GFDL) CM2.1 climate model, specifically: GFDL CM2.1, 20C3M (run5) climate of the 20th Century experiment (20C3M) output for IPCC AR4 and US CCSP.

In 2004, a new family of GFDL climate models (the CM2.x family) was first used to conduct climate research. The GFDL CM2.x models have become the workhorse model for GFDL's climate research. They are being applied to topics focusing on decadal-to-centennial (deccen) time scale issues (including multi-century control experiments and climate change projections), as well as to seasonal-to-interannual (si) problems, such as El Niño research and experimental forecasts.