Near Real Time analyzed maps of air quality in Europe Cécile Honoré, Laurence Rouïl

DCO - 08/09/ titre - 2 Built for operational purposes: Since 2004, in France public information related to pollution episodes (thresholds exceeded) can be driven not only by observations but also by numerical data and forecasts The PREV’AIR system :  a cooperative system for large scale air quality monitoring, forecasting and mapping over Western Europe and France ;  set up in 2003 by: Model development : MOCAGE + meteorological forecasts National Meteorological servicesMétéo France Model development : CHIMERENational Research CentreCNRS Builds up and hosts the NRT database AQ expertise for the Ministry National Agency of Environment ADEME Builds up and hosts the PREV’AIR system AQ expertise for the Ministry - CHIMERE dev. Public organization under the supervision of the Ministry of Ecology INERIS PREV’AIR :

DCO - 08/09/ titre - 3 Architecture of the PREV’AIR System 3D Chemistry Transport Models...  CHIMERE / IPSL-CNRS-INERIS  MOCAGE / METEO-France  open system to other models... … Driven by meteorological forecasts:  AVN / NCEP global data (+ MM5 higher resolution forecasts)  ARPEGE, ALADIN... Using input data:  emissions inventory (EMEP)  boundary conditions (LMDZ-INCA)  land-use (GLCF data base) NRT observation data:  BASTER/ADEME NRT database centralizes data from 40 French local AQ monitoring networks  and some data from Germany, Italy…. Chemical forecasts Low and high resolution meteorological forecasts Numerical forecast data Forecast s (maps) French NRT data (BASTER) Analyses (maps) Observation s (maps) Others partners NRT data...

DCO - 08/09/ titre - 4 Modelled concentrations corrected with observations:  Observations collected in real-time for 150 stations  Optimal interpolation approach using a kriging method  Available at J+0 with updates (twice a day in summer) if near real time observations available For the day before and the current day  Current status information available on the web sites, media, etc...  Allows an analysis of the pollution episodes developments Ozone and PM10 analyzed maps provided by PREV’AIR = + observations Simulations and observationsAnalysed maps and observations

DCO - 08/09/ titre - 5 How to proceed : Kriging on Model Errors (Innovations) Weights are computed so that: Analyzed concentration Innovation model simulations observations

DCO - 08/09/ titre - 6 Kriging on Model Errors (Innovations)  Need to know the spatial correlation pattern of the model error (the variogram)  Hypotheses for variance-covariance matrix:  Homogeneity and Isotropy:  « exponential » model  No nugget effect (variogram goes to zero)  Need to adjust :  Model for variogram (shape and parameters)  Choice of measurement stations : how many, typology, where...  Choice, if necessary, of external variables (land cover, population density, emissions…) 07/22/2006

DCO - 08/09/ titre - 7 Towards an European perspective…. Informal bilateral cooperation between PREV’Air consortium and countries interested in getting near-real time analyzed information Cooperation with organisations interested in using the CHIMERE model : Italy, the Netherlands, Portugal, Spain... The GMES framework (Global Monitoring for Environment and Security) : development of operational and pre-operational services devoted to air quality monitoring based on models, in-situ data and satellite data:  GEMS (6FP) coordinated by ECMWF : scientific purposes  PROMOTE (ESA funded) : operational concerns Interest EEA to support the implementation of near real-time air quality analyzed maps all over Europe through the GMES/PROMOTE initiative

DCO - 08/09/ titre - 8 Examples : Near real-time ozone data over Europe:  07/12/2006, 07/18/2006 and 07/22/2006  766, 757, 742 sites from NRT database  298, 295, 288 rural sites (green dots)  224, 223, 218 suburban sites (blue dots)  244, 239, 236 urban sites (black dots) Kriging is performed on peaks  provided that 50% of hourly data are available Ozone measurement sites on 07/12/2006

DCO - 08/09/ titre /12/2006: Rural sites only Simulation and Observations Analysis and Observations Correction = simulation - analysis

DCO - 08/09/ titre - 10 Evaluation of the benefits of the analyis 07/12/2006, rural sites only  RMSE_m 21.7 ug/m3 (model RMSE)  RMSE_a 16.5 ug/m3 (cross validation)  RMSE_v 17.4 ug/m3 (independent sites) Verification against independent (suburban and urban) sites

DCO - 08/09/ titre - 11 Analysis: rural sites only, 07/12/2006 Model + innovations (left) Variance (right)

DCO - 08/09/ titre - 12 Simulation and Observations Analysis and Observations 07/18/2006: rural and suburban sites 07/18/2006, rural sites only RMSE_m 20.0 ug/m3 (model RMSE) RMSE_a 17.2 ug/m3 (cross validation) RMSE_v 20.2 (independent sites)

DCO - 08/09/ titre - 13 Conclusions  Improved ozone concentration maps can be obtained on a daily (even hourly) basis thanks to models and near real time observation data  Allows a reliable representation of pollution patterns, and an accurate evaluation of pollution events  Method operationally run in France by the PREV’AIR system  Feasibility is shown for Europe with the near real time database built by EEA -> a new service for the Member States ? Perspectives  Application for PM data (PM10 first)  Use of new type a information : satellite retrievals for instance (PROMOTE)  An exchange system where the numerical data issued from analyses could be sent and used by the Member states for their own needs...  A precious database for the scientists for model improvement….