Abstract:

This documentation describes the minimizations done in ARPEGE/IFS, for example in the 3DVAR and 4DVAR assimilation. First some algorithmic aspects are recalled about minimizers and solving of linear algebra systems. There is then a specific description of the minimizers employed in ARPEGE/IFS (M1QN3, N1CG1 and CONGRAD) and of the applications using these minimizers.

RESUME:

CETTE DOCUMENTATION DECRIT LES MINIMISATIONS FAITES DANS ARPEGE/IFS, PAR EXEMPLE DANS LES ASSIMILATIONS 3DVAR ET 4DVAR. ON RAPPELLE D’ABORD QUELQUES NOTIONS SUR LES MINIMISEURS ET SUR LA RESOLUTION DES SYSTEMES LINEAIRES. ON FOURNIT ENSUITE UNE DESCRIPTION SPECIFIQUE DES MINIMISEURS UTILISES DANS ARPEGE/IFS (M1QN3, N1CG1 ET CONGRAD) ET DES APPLICATIONS UTILISANT CES MINIMISEURS.

Contents:

– 1/ Introduction.
– 2/ Some algorithms of minimization and of linear systems solving.
– 3/ Available minimizers in the ARPIFS and ALGOR libraries: description and organigrammes.
– 4/ Configurations of use of minimizations, and simulators.
– 5/ Modules and namelists.
– 6/ Bibliography.