Laboratoire des Écoulements Géophysiques et Industriels

Nos tutelles


Nos partenaires


Accueil > Grands équipements > La plateforme tournante Coriolis > Projets de recherche > Archives 2007

Using data assimilation in laboratory experiments of geophysical flows

Galmiche, M. , Sommeria, J. , Brasseur, P. , Verron, J. J. Marine Systems, 65 (1). (2007)

Data assimilation is used in numerical simulations of laboratory experiments in a stratified, rotating fluid. The experiments are
performed on the large Coriolis turntable (Grenoble, France), which achieves a high degree of similarity with the ocean, and the
simulations are performed with a two-layer shallow water model, using the SEEK method for data assimilation. Since the flow is
measured with a high level of precision and resolution, a detailed analysis of a forecasting system is feasible. The procedure is tested
for the baroclinic instability of a two-layer vortex. It is shown that the method of data assimilation properly captures the details of the
initial flow perturbation. Then it is shown by sensitivity studies that an error of the model, attributed to small non-hydrostatic effects,
can be distinguished from the error growth associated with the intrinsic instability of the system. Finally, it is experimentally
demonstrated that the velocity field in the lower layer can be well controlled by data assimilation limited to the top layer.