Scientific Commons: Eric Blayo

AGRIF: Adaptive Grid Refinement In Fortran (2008)

This report presents AGRIF a Fortran90 package for the integration of adaptive mesh refinement (AMR) features within a finite difference numerical model. The package mainly consists in two parts. It...

AGRIF: Adaptive Grid Refinement In Fortran (2008)

Debreu, Laurent, Blayo, Eric

This report presents AGRIF a Fortran90 package for the integration of adaptive mesh refinement (AMR) features within a finite difference numerical model. The package mainly consists in two parts. It...

Optimized global-in-time Schwarz algorithm for diffusion equations with discontinuous and spatially variable coefficients (2008)

Lemarié, Florian, Debreu, Laurent, Blayo, Eric

In this report we present a global-in-time non-overlapping Schwarz method applied to the one dimensional unsteady diffusion equation. We address specifically the problem with discontinuous diffusion...

4D Variational Data Analysis with Imperfect Model (2008)

Vidard, Arthur, Blayo, Eric, Le Dimet, François-Xavier, Piacentini, Andrea

One of the main hypothesis made in variational data assimilation is to consider that the model is a strong constraint of the minimization i.e. that the model describes exactly the behavior of the...

4D Variational Data Analysis with Imperfect Model (2008)

Vidard, Arthur, Blayo, Eric, Le Dimet, François-Xavier, Piacentini, Andrea

One of the main hypothesis made in variational data assimilation is to consider that the model is a strong constraint of the minimization i.e. that the model describes exactly the behavior of the...

Optimized global-in-time Schwarz algorithm for diffusion equations with discontinuous and spatially variable coefficients (2008)

Lemarié, Florian, Debreu, Laurent, Blayo, Eric

In this report we present a global-in-time non-overlapping Schwarz method applied to the one dimensional unsteady diffusion equation. We address specifically the problem with discontinuous diffusion...

Reduced-order 4D-Var: a preconditioner for the Incremental 4D-Var data assimilation method (2007)

Robert, Céline, Blayo, Eric, Verron, Jacques

This study demonstrates how the incremental 4D-Var data assimilation method can be applied efficiently preconditione d in an application to an oceanographic problem. The approach consists in...

Comparison of reduced-order, sequential and variational data assimilation methods in the tropical Pacific Ocean (2007)

Robert, Céline, Blayo, Eric, Verron, Jacques

This paper presents a comparison of two reduced-order, sequential and variational data assimilation methods: the SEEK filter and the R-4D-Var. A hybridization of the two, combining the variational...

A reduced-order strategy for 4D-Var data assimilation (2007)

Robert, Céline, Durbiano, S., Blayo, Eric, Verron, Jacques, Blum, Jacques, Le Dimet, François-Xavier

This paper presents a reduced-order approach for four-dimensional variational data assimilation, based on a prior EO F analysis of a model trajectory. This method implies two main advantages: a...

A reduced-order strategy for 4D-Var data assimilation (2007)

Robert, Céline, Durbiano, S., Blayo, Eric, Verron, Jacques, Blum, Jacques, Le Dimet, François-Xavier

This paper presents a reduced-order approach for four-dimensional variational data assimilation, based on a prior EO F analysis of a model trajectory. This method implies two main advantages: a...

Reduced-order 4D-Var: a preconditioner for the Incremental 4D-Var data assimilation method (2007)

Robert, Céline, Blayo, Eric, Verron, Jacques

This study demonstrates how the incremental 4D-Var data assimilation method can be applied efficiently preconditione d in an application to an oceanographic problem. The approach consists in...

Comparison of reduced-order, sequential and variational data assimilation methods in the tropical Pacific Ocean (2007)

Robert, Céline, Blayo, Eric, Verron, Jacques

This paper presents a comparison of two reduced-order, sequential and variational data assimilation methods: the SEEK filter and the R-4D-Var. A hybridization of the two, combining the variational...

Efficient interface conditions for the coupling of ocean models (2007)

Audusse, Emmanuel, Blayo, Eric, Halpern, Laurence, Japhet, Caroline, Martin, Véronique, Nourtier-Mazauric, Elise

Although the two-way nesting is the most usual coupling method in the ocean community, it does not address the correct problem but an approximation, and does not ensure enough regularity through the...

Efficient interface conditions for the coupling of ocean models (2007)

Audusse, Emmanuel, Blayo, Eric, Halpern, Laurence, Japhet, Caroline, Martin, Véronique, Nourtier-Mazauric, Elise

Although the two-way nesting is the most usual coupling method in the ocean community, it does not address the correct problem but an approximation, and does not ensure enough regularity through the...

Optimized Schwarz waveform relaxation algorithms with nonconforming time discretization for coupling convection-diffusion problems with discontinuous coefficients (2007)

Blayo, Eric, Halpern, Laurence, Japhet, Caroline

We present and study an optimized Schwarz Waveform Relaxation algorithm for convection-diffusion problems with discontinuous coefficients. Such analysis is a first step towards the coupling of...

Optimized Schwarz waveform relaxation algorithms with nonconforming time discretization for coupling convection-diffusion problems with discontinuous coefficients (2007)

Blayo, Eric, Halpern, Laurence, Japhet, Caroline

We present and study an optimized Schwarz Waveform Relaxation algorithm for convection-diffusion problems with discontinuous coefficients. Such analysis is a first step towards the coupling of...

Nesting ocean models (2007)

Blayo, Eric, Debreu, Laurent

This note is focused on the problem of providing boundary conditions for regional ocean models. It is shown that usual methods generally do not address the correct problem, but more or less...

Nesting ocean models (2007)

Blayo, Eric, Debreu, Laurent

This note is focused on the problem of providing boundary conditions for regional ocean models. It is shown that usual methods generally do not address the correct problem, but more or less...

Comparison of reduced-order, sequential and variational data assimilation methods in the tropical Pacific Ocean (2007)

Robert, Céline, Blayo, Eric, Verron, Jacques

This paper presents a comparison of two reduced-order, sequential and variational data assimilation methods: the SEEK filter and the R-4D-Var. A hybridization of the two, combining the variational...

Reduced-order 4D-Var: a preconditioner for the Incremental 4D-Var data assimilation method (2007)

Robert, Céline, Blayo, Eric, Verron, Jacques

This study demonstrates how the incremental 4D-Var data assimilation method can be applied efficiently preconditione d in an application to an oceanographic problem. The approach consists in...

A reduced-order strategy for 4D-Var data assimilation (2007)

Robert, Céline, Durbiano, S., Blayo, Eric, Verron, Jacques, Blum, Jacques, Dimet, François-Xavier Le

This paper presents a reduced-order approach for four-dimensional variational data assimilation, based on a prior EO F analysis of a model trajectory. This method implies two main advantages: a...

Dynamic Load Balancing for Adaptive Mesh Ocean Circulation Model (2007)

Blayo, Eric, Debreu, Laurent, Mounié, Grégory, Trystram, Denis

This paper reports the parallel implementation of adaptive mesh refinement within finite difference ocean circulation models. The implementation is based on the model of Malleable Tasks with...

Dynamic Load Balancing for Adaptive Mesh Ocean Circulation Model (2007)

Blayo, Eric, Debreu, Laurent, Mounié, Grégory, Trystram, Denis

This paper reports the parallel implementation of adaptive mesh refinement within finite difference ocean circulation models. The implementation is based on the model of Malleable Tasks with...

Revisiting open boundary conditions from the point of view of characteristic variables (2007)

Blayo, Eric, Debreu, Laurent

This paper emphasizes the peculiar role of characteristic variables in the design of open boundary conditions (OBCs). It is shown that local OBCs leading to positive results in previous comparative...

Revisiting open boundary conditions from the point of view of characteristic variables (2007)

Blayo, Eric, Debreu, Laurent

This paper emphasizes the peculiar role of characteristic variables in the design of open boundary conditions (OBCs). It is shown that local OBCs leading to positive results in previous comparative...

Compact finite difference schemes for shallow-water ocean model (2006)

Kazantsev, Christine, Kazantsev, Eugène, Blayo, Eric

In this paper, we test some high order numerical schemes on simple oceanic models. We first compare fourth-order and sixth-order compact schemes with the classical second-order centered scheme on the...

Compact finite difference schemes for shallow-water ocean model (2006)

Kazantsev, Christine, Kazantsev, Eugène, Blayo, Eric

In this paper, we test some high order numerical schemes on simple oceanic models. We first compare fourth-order and sixth-order compact schemes with the classical second-order centered scheme on the...

Dynamic Load Balancing for Ocean Circulation Model with Adaptive Meshing (2005)

Blayo, Eric, Debreu, Laurent, Mounié, Grégory, Trystram, Denis

This paper reports the parallel implementation of adaptive mesh refinement within finite difference ocean circulation models. The implementation is based on the model of {\it Malleable Tasks} with...

Dynamic Load Balancing for Ocean Circulation Model with Adaptive Meshing (2005)

Blayo, Eric, Debreu, Laurent, Mounié, Grégory, Trystram, Denis

This paper reports the parallel implementation of adaptive mesh refinement within finite difference ocean circulation models. The implementation is based on the model of {\it Malleable Tasks} with...

Modélisation et assimilation de données en océanographie (2004)

Blayo, Eric