Keywords: comparison with observations, forecast, mass consistent flow model, wind field modelling
Validation of a mass consistent flow model as part of a decision support system
In the context of real time (online) decision support systems for nuclear installations, atmospheric dispersion and deposition has to be calculated for a mesoscale area. Typically, the wind field in this area is influenced by topography. Therefore, simple Gaussian type modelling is not appropriate. Initiated and funded by the Bundesamt fur Strahlenschutz, simple (diagnostic mass consistent) flow models were investigated which, with readily available data, can realistically simulate the wind field in a large area. The effect of different initialisation modes of the model has been evaluated. The flow model is one component of a model chain. Other important parts are modules to calculate the atmospheric dispersion, the radiation exposure and counter measures. The initialisation of the flow model has been done based on a) local meteorological observations, typical for a nuclear site, b) prognostic data of the Deutschland-Modell (operational weather forecast model up to the end of 1999) of the Deutscher Wetterdienst, and c) a combination of both datasets a) and b). The present paper deals mainly with the performance of a mass consistent model initialised with the results of an operational weather forecast model.