A one year evaluation of the CTM CHIMERE using SURFEX/TEB within the high resolution NWP models ALARO and ALADIN for Belgium

At the Royal Meteorological Institute of Belgium the chemical transport model (CTM) CHIMERE runs at a spatial resolution of 7 × 7 km on a domain, covering Belgium and The Netherlands (680 × 680 km). The CTM is first run on a coarse resolution of 50 km covering Western Europe, using the meteorological fields of ECMWF. The emission database is provided by EMEP. The output of this model run is used as input for the boundary conditions for the coupled high resolution chemical transport model run. From previous studies, it has been shown that this one-way nested coupling with the limited area NWP models ALADIN and ALARO (7 × 7 km) already improved significantly the modelling of ozone concentrations by improving the physical parameterization, i.e. cloud cover, surface temperature, surface sensible heat flux, surface latent heat flux and relative humidity fields. The emission database used as input for this high resolution model is the TNO/GEMS emission database. In this study, we will also investigate the influence on the modelling of particulate matter when the CTM is coupled to these different high resolution NWP-configurations. We will investigate the air quality model forecast performance for a three day lead time on a daily basis, covering a one year time period (2008), implementing inline a new land surface scheme (SURFEX) – with and without taking into account The Town Energy Balance (TEB) – on the modelled ozone- and particulate matter concentrations.