COMPARATIVE SENSITIVITY STUDY FOR OPERATIONAL SHORT-RANGE ATMOSPHERICDISPERSION MODELS

Eight atmospheric dispersion models are compared in a sensitivity stud y in which the responses towards variations in model input parameters are evaluated. For a single source the values of eight practical model input parameters are varied. The model response is evaluated by exami ning the maximum value of the 98th percentile of the hourly averaged c oncentration values. The results are represented by means of a sensiti vity indicator relating the standard deviation of the parameter variat ions to the standard deviation of the resulting maximum 98th percentil e variations. The parameters studied in this exercise are grid resolut ion, stack height, flue gas temperature, source location, plant capaci ty, mass flow-rate, roughness length and meteorological time series. T he participating models are AUSTAL86 (TA-Luft), IFDM (VITO), ISCST2 (E PA), OML (NERI), OPS (RIVM), PLUIMPLUS (TNO), STACKS (KEMA) and UK-ADM S (CERC). The meteorological databases were chosen by the participants , being representative for their typical model applications. Source em ission data, however, were prescribed in order to provide the same ini tial conditions.