Performance assessment of CHIMERE and EURAD-IM’ dust modules

The purpose of this study is to investigate how two different atmospheric 3D modelling systems, with different dust modules, simulate a Saharan dust episode, using satellite data and in-situ observations to validate their performances. The episode occurred during 19–23 February 2016 and impacted the Iberian Peninsula. The two numerical modelling systems applied are the CHIMERE and the EURAD-IM chemistry transport models with different dust modules, both forced by the same WRF meteorological input. A common domain and resolution (27 × 27 km2) was adopted for the modelling setup. The comparison and evaluation of the two modelling results have shown that both models are able to capture the occurrence of the natural event, which was initiated by a cut-off low above the coast of Morocco, inducing a strong meridional transport of dust loaded air from Algeria straight towards eastern parts of the Iberian Peninsula. The most notable differences between the two model outputs concern the emission strengths and the emission source regions. In fact, different emission patterns and strengths are simulated by each model despite they use the same soil database, identical clay/silt/sand contribution for each soil type, and the same meteorological simulation. In general, CHIMERE simulates higher PM10, PM2.5, and dust concentrations than EURAD-IM for this event. In the South of Portugal, CHIMERE shows better agreement with observations, while in Central Portugal, EURAD-IM is closer to particle related measurements.