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From 14 June 2021 to 16 June 2021

Data assimilation

nasri |  

Deadline for registration: 15 days before the starting date of each training
Duration : 3 days / (21 hours)

Before signing up, you may wish to report us any particular constraints  (schedules, health, unavailability…)  at the following e-mail address : training@cerfacs.fr


Satisfaction index


In June 2019, 100% of participants were satisfied or very satisfied


Data assimilation is an important component of modelling in a number of applications in the geosciences and in engineering. This training course will provide an overview of the theory and practice of data assimilation. First, the basic concepts from statistical estimation theory and nonlinear optimization will be given. The classical variational and Kalman filtering approaches to data assimilation will then be described. The lectures will also touch upon more specialized topics including covariance modelling and estimation, advanced minimization algorithms, preconditioning, and hybrid ensemble-variational methods. The lectures on the theory will be complemented by both practical exercises and presentations on specific applications at CERFACS in the geosciences (oceanography, atmospheric chemistry, and/or hydrology/hydraulics).

Objective of the training

The objectives are to learn the key aspects of data assimilation, to understand the theory behind the methodologies, and to make the link with state estimation in the geosciences through specific applications.

Learning outcomes

On completion of this training you will be able to:

  • give a grounded opinion about advanced methods in data assimilation: variational assimilation, the Kalman filter, and their ensemble variants;
  • apply data assimilation and covariance modelling methods to simple problems;
  • appreciate the importance of and critical issues in data assimilation for real-world applications.

Target participants

This training session is for engineers, physicists, computer scientists and numerical analysts wishing to learn the fundamentals of data assimilation and the numerical methods to develop data assimilation applications.


In order to follow this course, you need to:

  • know basics methods in numerical linear algebra,
  • have a background in statistics and probability theory.

To verify that the prerequisites are satisfied, the following questionnaires must be completed. You need to get at least 75% of correct answers in order to be authorized to follow this training session. If you don’t succeed it, your subscription will not be validated. You only have two chances to complete them.

Questionnaire 1 : Numerical Analysis

Questionnaire 2 : Statistical Analysis

Scientific contacts: Selime Gürol & Anthony Weaver


  • Trainees/PhDs/PostDocs : 210 €
  • CERFACS shareholders/CNRS/INRIA : 600 €
  • Public : 1200 €


(Every day from 9h to 17h30)

Day 1:

Basic concepts and methodologies of data assimilation
Application from Earth sciences

Day 2:

Variational data assimilation
Covariance modelling and estimation

Day 3:

The Kalman filter and Ensemble Kalman filter
Hybrid ensemble-variational methods
Application from Earth sciences

Evaluation of prior learning

A final exam will be conducted during the training.


First 360-degrees Large-Eddy Simulation of a full engine

Jérôme DOMBARD |  17 June 2020

Within the PRACE project FULLEST (First fUlL engine computation with Large Eddy SimulaTion), a joint collaboration between CERFACS, SAFRAN and AKIRA technologies, Dr. C. Pérez Arroyo (post doctoral fellow at CERFACS) has carried out under the supervision of Dr. J. Dombard the first high-fidelity simulation of a part of the real engine DGEN380 (for now, from the fan to the combustion chamber). This 360-degrees integrated large-eddy simulation contains around two billion cells on the three instances, carried out with the AVBP code of CERFACS.  The CPU cost is obviously large but still within reach, performing around one turn of fan during 5 days over 14400 skylake cores. Post-treatments are in progress and already show, among other complex phenomena, a strong interaction between the high pressure compressor and the combustion chamber (see forthcoming paper GT2020-16288 C. Pérez Arroyo et al). Below a video showing: in the fan an isosurface at mid-height of the vein colored by the Mach number, in the high pressure compressor a gradient of density, in the bypass of the combustion chamber the static pressure and in the flame tube a temperature field. One of the goals of the project is to create a high-fidelity unsteady database to study interactions between modules and may help other teams to develop new lower order models and/or validate existing ones. Beyond the feasibility and the maturity of the AVBP code, this kind of calculation is an important milestone for the aeronautical industry and would allow to apprehend earlier in the design the effect of integration and installation and thus, to reduce the cycle and therefore the cost of the future aircraft engines. We acknowledge PRACE for awarding us access to Joliot-Curie (Genci) hosted at CEA/TGCC, FRANCE, Safran Tech and DGAC fundings within the project ATOM, along with the invaluable technical support at...Read more

B. Cuenot distinguished as Program Chair of international Symposium on Combustion

superadmin |  29 May 2020

B. Cuenot has been distinguished as Program Chair for the 39th International Symposium on Combustion, to be held in Vancouver (Canada) in 2022. The International Symposium on Combustion is a major event for the combustion community, where the current best research is presented.Read more