Coupling of Air Quality and Weather Forecasting: Progress and Plans at met.no

Air quality modelling at met.no consists of three different systems, all in off-line coupling to our numerical weather prediction models. For emergency purposes we have the “Severe Nuclear Accident Program” (SNAP) model, a Lagrangian particle model transporting gases, noble gases, particles of different size and density. The modeled processes are: advection and diffusion (Random Walk), dry deposition (gravitational settling velocity for particles) and wet deposition (function of size and precipitation for particles). The model is operated by forecasters and run on meteorological input from operational HIRLAM (10 and 20km horizontal resolution) and from ECMWF. The urban air quality information system runs operationally at met.no and consists of the chemical dispersion model AirQUIS developed at Norwegian Institute for Air Research and the non-hydrostatic NWP model MM5 in 1km horizontal resolution nested in HIRLAM. During the winter season 2006/2007 the UK Met Office Unified model is introduced to replace MM5, and a new interface to AirQUIS is built. The Unified EMEP model is simulating atmospheric transport and deposition of acidifying and eutrophying compounds, as well as photooxidants over Europe. The model domain covers Europe and the Atlantic Ocean. Typically, the model simulates 1 year period of the transport and the current results of the model runs are available for the years 19980, 1985, 1990 and each year from 1995 to 2004. The Unified EMEP models uses meteorological data from PARLAM-PS model, a dedicated version of the HIRLAM model.