Skip to Main content Skip to Navigation
New interface
Conference papers

Some tools for focusing variational data assimilation in ocean modelling

Eric Blayo 1 
1 MOISE - Modelling, Observations, Identification for Environmental Sciences
Inria Grenoble - Rhône-Alpes, LJK - Laboratoire Jean Kuntzmann, Grenoble INP - Institut polytechnique de Grenoble - Grenoble Institute of Technology
Abstract : Some tools are presented, which aim is to concentrate the effect of data assimilation on particular aspects of interest.
In a first part, a reduced order approach for 4D-Var data assimilation is described. The control space is defined as the span of a few vectors representing a significant part of the system variability. It is shown that such an approach can lead to significant improvements, both in terms of the quality of the solution and of the computational efficiency, with regard to data assimilation with a full control vector. However this approach presents also several limitations. In particular, the choice and the evolution of the reduced basis are discussed.
In a second part, we address the problem of variational data assimilation for nested models. An adjoint formulation is derived, and it is shown in particular that assimilation considering the whole multigrid system can lead to improved results with regard to assimilation in the high resolution model only.
Examples of applications will be given in the context of ocean modelling
Document type :
Conference papers
Complete list of metadata
Contributor : Eric Blayo Connect in order to contact the contributor
Submitted on : Thursday, December 4, 2008 - 10:45:42 PM
Last modification on : Friday, April 22, 2022 - 9:02:01 AM


  • HAL Id : inria-00344505, version 1



Eric Blayo. Some tools for focusing variational data assimilation in ocean modelling. Workshop Statistical Modeling of Extremes in Data Assimilation and Filtering Approaches, Jun 2008, Strasbourg, France. ⟨inria-00344505⟩



Record views