Seasonal weather forecasts for crop yield modelling in Europe

Within the European DEMETER project, ensembles of global coupled climate models have shown some skill for seasonal climate prediction. Meteorological outputs of the seasonal prediction system were used in a crop yield model to assess the performance and usefulness of such a system for crop yield forecasting. An innovative method for supplying seasonal forecast information to crop simulation models was developed. It consisted in running a crop model from each individual downscaled member output of climate models. An ensemble of crop yield was obtained and a probability distribution function (PDF) was derived. Preliminary results of wheat yield simulations in Europe using downscaled DEMETER seasonal weather forecasts suggest that reliable crop yield predictions can be obtained using an ensemble multi-model approach. When compared to the operational system, for the same level of accuracy, earlier crop forecasts are obtained with the DEMETER system. Furthermore, PDFs of wheat yield provide information on both the yield anomaly and the uncertainty of the forecast. Based on the spread of the PDF, the user can directly quantify the benefits and risk of taking weather-sensitive decisions. It is shown that the use of ensembles of seasonal weather forecast brings additional information for the crop yield forecasts and therefore has valuable benefit for decision-making in the management of European Union agricultural production.