The International Land Model Benchmarking (ILAMB) project is a model-data intercomparison and integration project designed to assess and improve land models and, in parallel, improve the design of new measurement campaigns to reduce uncertainties associated with key land surface processes. The goals of ILAMB are to: 1. develop internationally accepted benchmarks for land model performance, 2. promote the use of these benchmarks by the international community for model intercomparison, 3. strengthen linkages between experimental, remote sensing, and climate modeling communities in the design of new model tests and new measurement programs, and 4. support the design and development of a new, open source, benchmarking software system for use by the international community.

Improving the representation of land surface processes in climate models requires extensive comparison of model results with observations. This process is difficult and time intensive. Past data-model intercomparisons have strengthened the representation of key processes in land models, but often this information has not been easily accessible for use by other modeling teams or in future intercomparisons. Further, the development of sophisticated model diagnostics programs—that can fully exploit the richness of large Earth System data sets like satellite or Fluxnet measurements—are outside the scope of any single modeling center or principal investigator. Thus, an important advance for the field is the development of a community-based model evaluation system that is open source and modular, allowing for contributions by many different modeling and measurement teams.

Here, we will review progress of the ILAMB project and focus on plans and initial metrics that have been developed to assess land model water and energy cycles.