The LOTOS-EUROS model: description, validation and latest developments

In this paper, we present a validation study for oxidants and secondary inorganic aerosols using the new regional Chemistry Transport Model (CTM) Long Term Ozone Simulation (LOTOS) European Operational Smog (EUROS). The model is the product of the integration of the Netherlands Organisation for Applied Scientific Research (TNO) LOTOS model and the National Institute for Public Health and the Environment (RIVM) EUROS model. In addition to a model description, we present an overview of a validation of the model. The new model is able to capture the variability of ozone well, especially in summer. However, the exchange between the mixing layer and the free troposphere was assessed to be too low resulting in too high ozone levels at days with low ozone. Sulphate levels are underestimated, whereas the concentrations of nitrate and ammonium are in line with measured data. The performance of LOTOS-EUROS is similar to other regional models in Europe. Examples of new applications of the model are presented. These include the modelling of sea salt and heavy metals.