ARPEGE-Climat V5.1 Algorithmic Documentation (2009)

Arpege-IFS is a complex code designed not only for weather forecast or climate simulation, but also for data assimilation, forecast pre- and postprocessing. It has been extended, diversified and complexified since 1986 jointly by Météo-France and ECMWF. The present documentation restricts to the description of the French climate version of Arpege-IFS. Some features are not compatible with the version used by ECMWF. In this case, we will use the term Arpege. Some features are specific to the French climate version, and we will use the term Arpege-climat. The core of the model is cycle 32T0 of Arpege-IFS.

Contents :

1. Basic hypotheses and related constants
2. Dynamics equations
3. Spectral transforms
4. Semi-lagrangian discretization
5. Semi-Implicit spectral computations
6. Horizontal diffusion and nudging
7. Boundary conditions
8. Radiation
9. Clouds and turbulence
10. Large-scale precipitation
11. Vertical diffusion
12. Convection
13. Gravity wave drag
14. Soil, snow and vegetation
15. Diabatic terms
16. Diagnostics
17. References

See also the algorithmic documentation of the prognostic physics in ARPEGE-Climat (Deep convection, Shallow convection, Precipitation, Clouds and turbulence, Radiation).