TIGGE

The THORPEX Interactive Grand Global Ensemble, TIGGE, is planned as a multi-model, multi-analysis and multi-national ensemble prediction system. TIGGE will integrate user requirements for forecast information, developments in observing systems, targeting, adaptive data assimilation, and model improvements into a multi-model/multi-analysis ensemble prediction system. The initial basic components of TIGGE will be global ensembles run to around 14 days, including those run currently at a number of operational centres. These will be collected in near real time and stored in a common format in a number of central data servers for access by researchers in operational centres and the academic communities. This will facilitate research on combination and inter-comparison of different systems; it will become straightforward, for example, to compare the value of multi-model ensembles with those based on perturbations of a single model. The initial TIGGE archive became available for research use during 2007 and will contain ensemble forecasts from at least eight different national and pan-national weather services. The second phase of TIGGE (from 2008, depending on funding) will include additional products and the ability to obtain boundary conditions for ensembles of forecasts from limited-area models. It represents an exciting new opportunity for predictability research at academic institutions.