Development of a European Multimodel Ensemble system for seasonal to inTERannual prediction (DEMETER)

[Excerpt from: Palmer, T.N., A. Alessandri, U. Andersen, P. Cantelaube, M. Davey, P. Délécluse, M. Déqué, E. Díez, F. J. Doblas-Reyes, H. Feddersen, R. Graham, S. Gualdi, J.-F. Guérémy, R. Hagedorn, M. Hoshen, N. Keenlyside, M. Latif, A. Lazar, E. Maisonnave, V. Marletto, A. P. Morse, B. Orfila, P. Rogel, J.-M. Terres and M. C. Thomson, Development of a European Multi-Model Ensemble System for Seasonal to Inter-Annual Prediction (DEMETER), ECMWF Technical Memorandum 434, 2004 ] The DEMETER project (Development of a European Multi-model Ensemble System for Seasonal to Interannual Prediction) was conceived, and funded under the European Union Vth Framework Environment Programme.

The principal aim of DEMETER was to advance the concept of multi- model ensemble prediction by installing a number of state-of-the-art global coupled ocean-atmosphere models on a single supercomputer, and to produce a series of six-month multi-model ensemble hindcasts with common archiving and common diagnostic software. Such a strategy posed substantial technical problems, as well as more mundane but nevertheless important issues (e.g. on agreeing units in which model variables were archived).