4D Variational Data Assimilation for Locally Nested Models : complementary theoretical aspects and application to a 2D shallow water model - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue International Journal for Numerical Methods in Fluids Année : 2011

4D Variational Data Assimilation for Locally Nested Models : complementary theoretical aspects and application to a 2D shallow water model

Résumé

We consider the application of a four-dimensional variational data assimilation method to a numerical model, which employs local mesh refinement to improve its solution. We focus on structured meshes where a high-resolution grid is embedded in a coarser resolution one, which covers the entire domain. The formulation of the nested variational data assimilation algorithm was derived in a preliminary work (Int. J. Numer. Meth. Fluids 2008). We are interested here in complementary theoretical aspects. We present first a model for the multi-grid background error covariance matrix. Then, we propose a variant of our algorithms based on the addition of control variables in the inter-grid transfers in order to allow for a reduction of the errors linked to the interactions between the grids. These formulations are illustrated and discussed in the test case experiment of a 2D shallow water model.

Dates et versions

hal-00658105 , version 1 (09-01-2012)

Identifiants

Citer

Ehouarn Simon, Laurent Debreu, Eric Blayo. 4D Variational Data Assimilation for Locally Nested Models : complementary theoretical aspects and application to a 2D shallow water model. International Journal for Numerical Methods in Fluids, 2011, 66 (2), pp.135-161. ⟨10.1002/fld.2244⟩. ⟨hal-00658105⟩
183 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More