Status of an operational air quality monitoring and forecasting service utilising assimilated earth observation data.

As is well known, anthropogenic activities have altered the chemical composition of the atmosphere resulting not only in the loss of its natural protection against harmful UV radiation, but in the addition/increase of hazardous chemical constituents to the atmosphere near the surface. It is this fact that has lead to the funding of numerous EU, ESA, and global and national studies (e.g., APHEIS, CAFE) and to treaties and directives (e.g., CLRTAP, EU96/62 and daughter directives) aimed at understanding and mitigating these hazards. The studies and directives have prompted many research efforts into the modelling (for both monitoring and forecast) of ambient air quality and chemical weather. But because of the extent and constantly changing nature of the atmosphere, the use of earth observation (EO) data derived from satellites to study and monitor the atmosphere is a critical component of an integrated modelling system which also includes in-situ data. This presentation will highlight the progress made in implementing such an integrated system for forecast and modelling of several ambient atmospheric constituents at the German Remote Sensing Data Center of the German Aerospace Center (DFD-DLR). At the heart of the system is EURAD, a short range (48-72 hour) forecast model developed at the Rhenish Institute for Environmental Research (RIU) at the University of Cologne, consisting of components for meteorological, concentration, and deposition forecasts, as well as for emission rates of major pollutants. The development and implementation of EO data assimilation processes is part of an ongoing cooperation between DLR and RIU, and has resulted in an operational monitoring and forecasting system offering nested simulations which provide consistent modelling from local to continental scales.