In 1982, he became the first director of the Centre National de Recherches Météorologiques (CNRM, Toulouse), a position he held until the end of 1994.
He applied this consideration of irreversibility in the formulation of so-called Eddy-Damped Quasi-Normal (EDQNM) approximation with the Nice school (U. Frisch and collaborators)".
He then used the EDQNM approximation to realistically simulate homogeneous and isotropic turbulence in 2 and then 3 dimensions[1][2] and, in the latter case, showed the role of helicity, an innovative work taken up ten years later in the US to explain the dynamics of convective atmospheric systems.
In support of this numerical modeling work, he designed, organized and carried out, in the South-West of France, a large-scale international experimental campaign (F, GB, USA...), based on this concept: HAPEX-MOBLHY 86,[8] the first of a long series of large meteorological-hydrological campaigns still in progress within the framework of the international GEWEX program.
- Member of the Scientific Councils of Defense (1994-1997), Electricité de France (1996-2002), the Nuclear Energy Directorate of the CEA (2002-2018), the National Computer Center for Higher Education, CINES (2003-2006), the Research Foundation for Aeronautics and Space (2005-2011), the Strategic Committee for Intensive Computing (2009-2013), the Electricity Transmission Network, RTE (2011-2015); - President of the Scientific Councils of the National Geographic Institute (1998-2001), of the Program "Management and Impacts of Climate Change" (1998-2005), of the National Technological Research Center "Aeronautics and Space" (2002-2007), of the ORAP "Associative Organization on Parallelism" (2005-2009), of the "Intensive Computing" Program of the National Research Agency (2005-2007), of the EADS Corporate Foundation (2007-2010) ; - Member of the Advisory Committee of Deontology and Ethics of the Institute of Research for Development (2005-2013); - chairman of the Board of Directors of the GIP (Public Interest Grouping) "MEDIAS-France" (1994-2006); - President of the French Meteorological Society (1995-1997); - Executive Secretary of the MERCATOR inter-agency program for the development of operational oceanography (1997-2001); - Vice-president of the National Center for Technological Research "Aeronautics and Space" (2002-2007); - Member of the Steering Committee of the RTRA (Thematic Network of Advanced Research) STAE "Sciences and Technologies for Aeronautics and Space" (2007-2017).