Fund experiments on atmospheric hazards

The recent eruption of Eyjafjallajökull volcano and the radioactive releases from the NPP Fukushima highlight the importance of atmospheric dispersion models in predicting and assessing the consequences of such events. In the past three decades, dramatic progress has been made in weather analysis and forecast. No comparable advances, however, have been made in modelling crucial physical processes like turbulence and deposition which can fatally decide between success and failure of a dispersion prediction. To advance model development and evaluation1, observational data are badly needed. Long-range tracer experiments were made in North America2 in the 1980s and in Europe3 in 1994. Since then, no further campaigns were conducted. Consequently, the predictive capabilities of present atmospheric dispersion models remain poorly tested, hindering further model development. It is now time to perform new atmospheric tracer experiments on multiple scales. Such experiments should use non-hazardous, climate-neutral substances. The release term should be representative of a realistic scenario with varying source strengths. Based on access to a limited set of observations, modellers should estimate, in real time, the emission without knowing the actual release rates. The real values of Emitted and measured tracer should be distributed only after modellers have submitted their results. Subsequently, models and data reconstruction methods should be improved and re-tested. Such tracer experiments will p a long list of scientific and societal benefits. Confidence in models and emergency procedures will be re-enforced. Recent global events should serve us as a reminder that gaps still exist in our knowledge and investments in this field are needed.JRC.DDG.H.2-Climate change and air qualit