Annual Evaluation of Wrf-arw and Wrf-nmm Meteorological Simulations over Europe

The BSC-CNS is involved in the CALIOPE project (Baldasano et al., 2008), a national Spanish initiative that has as main objective to establish an air quality forecasting system for Spain coordinated by the Ministry of the Environment. The modeling system bases on the WRF-ARW model as meteorological driver (Figure 1). As is well known, air quality models are highly dependent on the quality of the meteorological inputs, and any improvement in meteorological fields should be maintained in chemistry models. Pérez et al. (2006) showed that an increase in 3oC of temperature can lead to an increase of 7.2 21.1 μg m-3 of ozone concentration in background areas. Moreover, moisture errors may impact in the formation of secondary organic aerosols and in the aqueous chemistry by modifying the OH radical concentrations, and an overestimation of wind speed will produce an increased mixing of pollutants within the boundary layer and a major advective effect, the result will be a simulation of lower background pollutant concentrations over the affected areas. One major characteristic of WRF model is that it has the possibility to be configured with different dynamical cores. The need to analyze the performance of the system under different configurations is then demanded. The main objective of the work is to analyze the skills of meteorological mesoscale models as drivers of air quality modeling system. For that purpose we planned to evaluate the 2 dynamical cores of the WRF modeling system, WRF-NMM (Janjic, 2003) and WRF-ARW (Skamarock and Klemp, 2008). WRF-NMM is currently the operational mesoscale meteorological model of NCEP and WRF-ARW is the research model of the NCAR. To evaluate both models, we have performed an annual simulation of the year 2004 over an European domain at 12 km of horizontal resolution, and the results of the models have