Monitoring Air Quality: the Role of OSSEs in Determining the Future Global Observing System
Lahoz, William1; Attie, Jean-Luc2; Abida, Rachid3; El Amraoui, Laaziz3; Hache, Emeric3; Ricaud, Philippe3; Peuch, Vincent-Henri4; Orphal, Johannes5
1NILU, NORWAY; 2University Toulouse, FRANCE; 3Meteo-France, FRANCE; 4ECMWF, UNITED KINGDOM; 5KIT, GERMANY

The need to monitor air quality is recognized world-wide. This involves, inter alia, measurements of key pollutants (e.g. ozone and carbon monoxide) in the lowermost troposphere at spatio-temporal scales relevant to policy makers (temporal frequencies of order less than 1 hour; spatial scales of order less than 10-15 km). This presentation identifies the role of data assimilation observing system simulation experiments (OSSEs) in determining the future global observing system to monitor air quality. Caveats associated with setting up and interpreting OSSEs are discussed. OSSEs performed to assess the added value of planned and proposed geostationary satellite platforms for monitoring air quality are presented to illustrate the concept.