A multiple gird approach for atmospheric composition - aware NWP forecasts with the ECMWF forecast system

Including prognostic atmospheric composition (AC) simulations in numerical weather predication or climate modelling application to exploit AC – weather feedbacks is often prohibited by the high computational cost of adding complex AC simulation to the weather or climate model.  There are in principle two approaches to solve this problem: (i) drastically reduce the complexity of the aerosol and chemistry simulations in the weather model, or (ii)  safe cost by reducing the spatial resolution of the model components simulating the AC processes and implement a coupling mechanism.  

At ECMWF a dual configuration forecast (dcfc) approach for the of the Integrated Forecasting System (IFS) has been developed based on the infrastructure for Object-Oriented Prediction System (OOPS). It enables the coupled simulation of a high-resolution application and a low-resolution application of the IFS and a coupling mechanism. The low-resolution model instance simulates the aerosol and chemistry-processes as activated for the operational AC forecasts by the Copernicus Atmosphere Monitoring Service (CAMS)  

We show first scientific results of this dual configuration forecast (dcfc) for a sever dust storm event in Europe in March 2022. We will discuss to what extent and at what computational cost the dcfc application can forecast the meteorological impact of the dust on radiation and 2m temperatures. We will compare the dcfc result to the more expensive integrated IFS-CAMS configuration as well as to NWP forecast using the aerosol climatology as currently applied in the ECMWF operational weather forecasts.