Validation of reactive gases and aerosols in the MACC global analysis and forecast system

摘要

The European MACC (Monitoring Atmospheric Composition and Climate) project ispreparing the operational Copernicus Atmosphere Monitoring Service (CAMS),one of the services of the European Copernicus Programme on Earth observationand environmental services. MACC uses data assimilation to combine in situand remote sensing observations with global and regional models ofatmospheric reactive gases, aerosols, and greenhouse gases, and is based onthe Integrated Forecasting System of the European Centre forMedium-Range Weather Forecasts (ECMWF). The global component of the MACCservice has a dedicated validation activity to document the quality of theatmospheric composition products. In this paper we discuss the approach tovalidation that has been developed over the past 3 years. Topics discussedare the validation requirements, the operational aspects, the measurementdata sets used, the structure of the validation reports, the models andassimilation systems validated, the procedure to introduce new upgrades, andthe scoring methods. One specific target of the MACC system concernsforecasting special events with high-pollution concentrations. Such eventsreceive extra attention in the validation process. Finally, a summary isprovided of the results from the validation of the latest set of daily globalanalysis and forecast products from the MACC system reported inNovember 2014.