Improving ozone forecasts over Europe by synergistic use of the LOTOS-EUROS chemical transport model and in-situ measurements

► Traditional modeling system misses high ozone peak. ► We assess the benefit of the synergistic use of model and measurements. ► The added-value of the data assimilation (DA) of ozone in-situ data is investigated. ► Study of the scaling factors of DA shows that no information can be carried into the forecast. ► In practice, the ozone maxima were better reproduced for both reanalysis and forecasting.