Improving the mass conservation in the semi-Lagrangian scheme of the IFS/HARMONIE model

Resumen

The global forecast model, Integrate Forecast System (IFS), of the European Center for MediumRange Weather Forecast (ECMWF), and the limited-area model, Hirlam Aladin Mesoscale Operation NWP in Europe (HARMONIE), developed by Aladin and Hirlam groups, both solved the 3D primitive equations and the evolution of the components of the atmosphere which are described by a continuity equation whose conserved quantity is the total mass of each component.
 
These NWP models have the same dynamic kernel, use hydrostatic pressure as the basis of its vertical coordinate and both introduce orography via a terrain-following vertical coordinate at the lowest model levels.