Obs4MIPs refers to a carefully selected set of well-established and documented datasets that have been organized according to the CMIP5 model output requirements and made available to the research community in the same way model data is accessed.  NASA/JPL and DOE/PCMDI initiated this activity with a focus on monthly mean near-global satellite products and a limited selection of higher frequency data.   Each obs4MIPs dataset corresponds to a field that is output in one or more of the CMIP5 experiments. This technical alignment of observational products with climate model output greatly facilitates model data comparisons. Guidelines have also been developed for Obs4MIPs product documentation that is of particular relevance for model evaluation. To summarize, products available via Obs4MIPs are:

1. Directly comparable to a model output field defined as part of CMIP5
2. Open to contributions from all data producers that meet the Obs4MIPs requirements
3. Well documented, with traceability to track product version changes
4. Served through ESGF

Obs4MIPs has gained considerable interest in various research communities, and since the acceptance of this paper the project has grown into an international activity with contributions now being made by NOAA, ESA and other satellite agencies.    PCMDI continues to provide leadership of this activity via the WCRP Data Advisory Council and the task team it has established to help further advance the project.

More project information is available at: https://www.earthsystemcog.org/projects/obs4mips