Variational Data Assimilation with a Semi-Lagrangian Semi-implicit Global Shallow-Water Equation Model and Its Adjoint

Li, Y.; Navon, I. M.; Courtier, P. et Gauthier, P. (1993). « Variational Data Assimilation with a Semi-Lagrangian Semi-implicit Global Shallow-Water Equation Model and Its Adjoint ». Monthly Weather Review, 121(6), pp. 1759-1769.

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Résumé

An adjoint model is developed for variational data assimilation using the 2D semi-Lagrangian semi-implicit (SLSI) shallow-water equation global model of Bates et al. with special attention being paid to the linearization of the interpolation routines. It is demonstrated that with larger time steps the limit of the validity of the tangent linear model will be curtailed due to the interpolations, especially in regions where sharp gradients in the interpolated variables coupled with strong advective wind occur, a synoptic situation common in the high latitudes. This effect is particularly evident near the pole in the Northern Hemisphere during the winter season. Variational data assimilation experiments of “identical twin” type with observations available only at the end of the assimilation period perform well with this adjoint model. It is confirmed that the computational efficiency of the semi-Lagrangian scheme is preserved during the minimization process, related to the variational data assimilation procedure.

Type: Article de revue scientifique
Informations complémentaires: © Copyright [1993] AMS (https://www.ametsoc.org/ams/index.cfm/publications/authors/journal-and-bams-authors/author-resources/copyright-information/copyright-policy/)
Mots-clés ou Sujets: Adjoint model, global model, semi-Lagrangian model, shallow water equation, variational data assimilation
Unité d'appartenance: Faculté des sciences > Département des sciences de la Terre et de l'atmosphère
Déposé par: Pierre Gauthier
Date de dépôt: 26 avr. 2016 18:01
Dernière modification: 26 mai 2016 14:19
Adresse URL : http://www.archipel.uqam.ca/id/eprint/8301

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