Comparison and validation exercises of the three atmospheric dispersion models in RODOS

During the EURANOS project three atmospheric dispersion models ATSTEP (ATSTEP, 2007), RIMPUFF (RIMPUFF, 1999), and DIPCOT (DIPCOT, 2009) used in the RODOS (Ehrhardt and Weis, 2000) decision support system were subject of comprehensive comparison and validation studies. The aim of the comparison exercise was a harmonisation of the models for a sample of representative, non-complex dispersion and deposition situations in the distance range below 100 km. Despite of different modelling and parameterisation the models should deliver similar results under these conditions. Furthermore validation studies were carried out with ATSTEP and DIPCOT using measured meteorological and contamination data from tracer dispersion field experiments. After minor model and parameter modifications final comparison calculations of the models with realistic numerical weather prediction (NWP) data have shown satisfactory consistency of the results.