The Evaluation of the Spanish Air Quality Modelling System: CALIOPE. Dynamics and Chemistry over Europe and Iberian Peninsula for 2004 at high horizontal resolution
In Europe, human exposure to air pollution often exceeds standards set by the EU commission (Directives 1996/62/EC, 2002/3/EC, 2008/50/EC) and the World Health Organization (WHO). Urban/suburban areas are predominantly impacted upon, although exceedances of particulate matter (PM10 and PM2.5) and Ozone (O3) also take place in rural areas. Within the CALIOPE project, a high-resolution air quality forecasting system, namely WRF-ARW/HERMES04/CMAQ/BSC-DREAM, has been developed and applied to the European domain (12x12 sq. km, 1hr) as well as the Spanish domain (4x4 sq. km, 1hr). The simulation of such high-resolution model system has been made possible by its implementation on the MareNostrum supercomputer. This contribution describes a thorough quantitative evaluation study performed for the reference year 2004. The WRF-ARW meteorological model contains 38 vertical layers reaching up to 50 hPa. The vertical resolution of the CMAQ chemistry-transport model for gas-phase and aerosols has been increased from 8 to 15 layers in order to simulate vertical exchanges more accurately. Gas phase boundary conditions are provided by the LMDz-INCA2 global climate-chemistry model. For the European simulation, emissions are disaggregated from the EMEP emission inventory for 2004 to the utilized resolution using the criteria implemented in the HERMES04 emission model. The HERMES04 model system, running through a bottom-up approach, is used to estimate emissions for Spain at a 1x1 sq. km horizontal resolution, every hour. In order to evaluate the performances of the CALIOPE system, the model simulation for Europe was compared with ground-based measurements from the EMEP and the Spanish air quality networks (total of 60 stations for O3, 43 for NO2, 31 for SO2, 25 for PM10 and 16 for PM2.5). The model simulation for Europe satisfactorily reproduces O3 concentrations throughout the year (annual correlation: 0.66) with relatively small errors: MNGE values range from 13% to 26%, and MNBE values show a slight negative bias ranging from -18% to 0%. These values lie within the range defined by the US-EPA (MNGE: +/- 30-35%; MNBE: +/- 10-15%. See US-EPA, 1991, 2005). NO2 is less accurately simulated, with a mean MNBE of -35% caused by an overall underestimation in concentrations. The reproduction of SO2 concentrations is relatively correct but false peaks are reported (mean annual MNBE=6%). The simulated variation of particulate matter is reliable, with a mean correlation of 0.57. The aerosol dynamics is well captured and false peaks are reduced by use of an improved 8-bin aerosol description in the BSC-DREAM dust model, but mean levels are still underestimated by a factor of two. The model simulation for Europe is used to force the nested high-resolution simulation of Spain. The performances of the latter will be also presented.
AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- 0345 ATMOSPHERIC COMPOSITION AND STRUCTURE / Pollution: urban and regional;
- 0365 ATMOSPHERIC COMPOSITION AND STRUCTURE / Troposphere: composition and chemistry