Curriculum vitae

Personal Information

Bérengère Dubrulle (b. 07/26/1965 in Dieppe, France).

Senior researcher at CNRS, SPHYNX Laboratory, SPEC, CEA Saclay, France.

Web: http://iramis.cea.fr/Pisp/berengere.dubrulle/

Personal information: 4 children (27, 26, 24 and 22 years)

Academic & Positions

1985-1989: Student at the Ecole Normale Supérieure de Jeunes Filles, Paris

1986-1987: M. Sc (DEA) in Quantum Mechanics (Paris VI University, France)

1987-1988: Visiting scholar at Radio Astronomy Laboratory (University of California, Berkeley)

1988-1990 Ph. D in Astrophysics with highest honours (Toulouse University, France)

Advisor: J-P. Zahn

1991: Post-doc at Meteorological Research Institute, Tsukuba, Japan.

1991-2000: CNRS Junior Scientist

1996: Habilitation à Diriger des Recherches in Physics (Paris VII University, France)

1998-1999: Visiting scientist in MMM division of NCAR, Boulder, Colorado

2000-Today: CNRS Senior Scientist (Exceptional class since October 2021)

Fellowships and Awards

1987: Georges Lurcy Fellowship

1987 & 1988: Amelia Earhart Fellowship

1993: CNRS Bronze Medal

2007: Pauli Fellow

2008: Victor Noury Prize from the French Academy of Science

2009-Today: Award (PES) for Outstanding Research of CNRS (renewed in 2013 and 2017)

2017: CNRS Silver Medal

2021: Lewis Fry Richardson Medal from the European Geophysical Union

Scientific profile

I received my PhD in astrophysics in 1990, after having worked on “Instabilities, turbulence and transport in accretion disks” with J-P. Zahn and U. Frisch. During my PhD and the following years, I worked on a new scenario to explain to explain the formation of solar system, based on hydrodynamical turbulence. Using data from laboratory flows, and chemical observations from space missions, I showed that the turbulence generated by nonlinear shear instabilities could produce giant vortices favouring grains condensation and planetesimal growth. This hypothesis is now the basis of many solar system scenarios.

In 1994, I started to work on explanation of turbulence intermittency. I explored scenarii based on log-Poisson statistics, finite size scale invariance, and non-locality of interactions.

In 2001, I joined the VKS team, to work on theoretical and experimental explanation of cosmic magnetic fields through turbulent dynamos. I participated in data campaigns and analysis of the Sodium experiment, and devised a Galerkin method to obtain 3D reconstruction of the magnetic field from sparse measurements. I supervised several post-doc and students to explore the influence of noise on the dynamo instability and show that it has an impeding influence. I also proposed to explain why dynamo in VKS has only been observed with ferro-magnetic disks via enhancement of the alpha effect mechanism by magnetic field collimation of shedding vortices.

In 2005, I started to work on modelling of the large-scale structures of geophysical and astrophysical flows. I adapted the statistical framework of Robert and Sommeria, built for 2D flows to cases with axisymmetry (2D1/2). My theory successfully reproduces features of the mean flow and its bifurcations observed in the von Karman experiment in Saclay. I further supervised 2 PhDs to interpret the turbulent bifurcation in terms of phase transition, analog to the ferro-paramagnetic transition. Since 2009, I applied these concepts in climate modelling, and work on the application and explanation of a min-max entropy production principle for prediction of temperature distribution at the Earth surface.

In 2009, I started collaborating with experimentalists in Grenoble and Lyon to study quantum turbulence. I proposed to build a von Karman experiment filled with Helium4 below and above the lambda point to study turbulence and dissipation processes in classical and quantum flow. The experiment was built in 2011 (SHREK experiment). I have participated to several experimental campaigns, and in data analysis. I have supervised several PhDs and post-docs in Saclay to conduct experiments in water on a scale 1:4 version of SHREK, for calibration and interpretation of the data.

Since 2015, I launched a new area of research, attempting to detect Holder singularities of Navier-Stokes equation in a laboratory turbulent flow by following in scale the extreme events inertial dissipation. We found that they correspond to non-trivial velocity topologies associated with possible footprints of singularities. A striking result of our exploration is the existence of localized significant non-viscous energy transfers even at the Kolmogorov scale. These transfers are taken into account neither by classical Direct Numerical Simulations (DNS) (usually cut above or at the Kolmogorov scale), nor by traditional turbulence models (following K41 phenomenology). Understanding these sub-Kolmogorov transfers and building a new turbulent model compatible is now my main objective. I have written an invited review paper entitled Beyond Kolmogorov cascades (JFM Perspectives, 2019) on this subject.

This work has been conducted in collaboration with theoreticians, numericians and experimentalists. Formation of solar system: D. Gautier, F. Hersant; Statistical Mechanics of Turbulence: F. Bouchet , P-H. Chavanis; Dynamo Effect: J-F. Pinton, N. Plihon, Ph. Odier, S. Fauve, F. Pétrélis, F. Daviaud, B. Gallet, S. Aumaitre, F. Ravelet (VKS Collaboration), S. Brun, C. Nore. Quantum Turbulence: B. Castaing, L. Chevillard, F. Chilla, B. Rousset, A. Girard, P. Diribarne, Ph. Roche, M. Gibert, F. Daviaud, A. Braslau, B. Gallet, I. Moukharsky (SHREK Collaboration). Wave Turbulence and Intermittency: S. Nazarenko, J-P. Laval. Climate: D. Paillard.

I have organized or co-organized 12 international workshops and conferences since 1993.

Research record

I have published over 160 peer-reviewed papers since 1987; my h-index is 47 (total citations: 8278; lead author of 38 papers, source: Google Scholar 29/05/22. I have published 1 Nature Communication and 15 PRL.

Community activities

I have been head of the French National Research Group (GDR) on Dynamo, and elected member of the National Committee of CNRS (Theoretical Physics division). I am presently member of the European Turbulence Committee of the European Mechanics Society and of the Conseil Scientifique de l’Observatoire Côte d’Azur.

I have been member of the National Committee for Planetology, of the Committee for Non-Linear Sciences, of the Committee Women in Sciences of the French Physical Society and of the French Committee for High Performance Computing.

I am member of the National Committee for Mechanics, of the Committee for Non-Linear Physics of the French Physical Society and of in Administrative Council of the French Physical Society

I am Divisional Associate Editor (section Fluid) at PRL since 2019.

I am Editor in Chief of Journal of Fluid Mechanics Perspectives since 2022.

I am Director of Les Houches School of Physics since 2021.

I lead a research group on turbulence at SPEC since 2007 about statistical modelling of turbulence. Its members are theoreticians and experimentalists.

I regularly work as reviewers for journals like PRL, Physics of Fluids, Physical Review E, Physical Review Fluids, J. Fluid Mech., NJP, Physica D.

I have supervised 12 postdocs and 20 PhD students. 22 of them have now permanent positions (6 are still finishing his PhD). 9 of them have CNRS or CEA permanent positions, 2 are assistant professors in engineering school (ENSTA), 7 are professors or assistant professors in Universities (China, Paris, Grenoble,Nice), 4 are in R&D departments of industrial groups, 1 is analyst at British Petroleum, 1 professor in preparatory school, 1 high-school teacher.

Scientific Outreach

I am co-author of a scientific book for children explaining climate physics: B. Dubrulle and V. Masson, Le Climat : de nos ancêtres à vos enfants, Collection Minipommes, Editions Le Pommier, 2005. During the last fifteen years, I made a hundred of talks in classes, sciences and book festivals, radio, TV to explain dynamo, turbulence and climate to general audience, including children age 8 to 14.

Featured Publications

(out of 155 publications, 3 344 citations without auto citations, and h=33 over the track-record source: ISI Web of Science 29/01/18).

New scenario for solar system

[1] B. Dubrulle, Differential Rotation as a source of angular momentum transfer in the solar nebula, (1993) Icarus 106 59-76.

[2] B. Dubrulle, L. Marie, Ch. Normand, F. Hersant, D. Richard and J-P. Zahn, An hydrodynamic shear instability in stratified disks, (2005) Astron. Astroph. 429 1-13. Suggests that the combination of shear plus stratification may be a source of turbulence in the solar nebula.

[3] B. Dubrulle, O. Dauchot, P-Y. Longaretti, F. Daviaud, F. Hersant, D. Richard and J-P. Zahn, Stability and transport in Taylor-Couette flow from analysis of experimental data, (2005) Phys. Fluids 17 095103. Derives a parameter free prescription for angular momentum transport in disks from analysis of experimental measurements.

Intermittency

[4] B. Dubrulle, Intermittency in fully developed turbulence: Log-Poisson statistics and generalized scale-covariance, (1994) Phys. Rev. Letters 73, 959-963.

[5] A. Arnéodo, C. Baudet, F. Belin, R. Benzi, B. Castaing, B. Chabaud, R. Chavarria, S. Ciliberto, R. Camussi, F. Chilla, B. Dubrulle, Y. Gagne, B. Hébral, J. Herweijer, M. Marchand, J. Maurer, J-F. Muzy, A. Naert, A. Noullez, J. Peinke, F. Roux, P. Tabeling, W. Van de Water, H. Willaime, Structure functions in

turbulence, in various flow configurations, at Reynolds number between 30 and 5000, using extended self-similarity, Europhys. Letter 34 (1996) 411.

[6] J-P. Laval, B. Dubrulle and S. Nazarenko, Non-locality and Intermittency in 3D Turbulence (2001) Phys. Fluid, 13 1995-2012. An explanation of intermittency based on non-locality of energy transfers.

[7] E.-W. Saw, P. Debue, D. Kuzzay, F. Daviaud, B. Dubrulle. On the universality of anomalous scaling exponents of structure functions in turbulent flows J. Fluid Mech., 837 (2018).

Dynamo

[8] R. Monchaux, M. Berhanu, M. Bourgoin, M. Moulin, Ph. Odier, J.-F. Pinton, R. Volk, S. Fauve, N. Mordant, F. Pétrélis, A. Chiffaudel, F. Daviaud, B. Dubrulle, C. Gasquet, L. Marié, and F. Ravelet Generation of a magnetic field by dynamo action in a turbulent flow of liquid sodium (2007) Phys. Rev. Letters 998 044502 The first experimental evidence of dynamo action in an unconstrained turbulent swirling flow. I participated in data analysis and interpretation.

[9] J-P. Laval, P. Blaineau, N. Leprovost, B. Dubrulle and F. Daviaud, Influence of turbulence on the dynamo threshold, (2006) Phys. Rev. Letters, 96 204503. This work shows that the turbulence has an impeding action on the dynamo threshold.

[10] F. Ravelet, B. Dubrulle, F. Daviaud, P. Ratie, Kinematic alpha Tensors and Dynamo Mechanisms in a von Karman Swirling Flow, (2012) Phys. Rev. Letters, 109, 024503. Computes the efficiency of the alpha mechanism due to vortices shredded by blades.

[11] J. Varela, S. Brun, B. Dubrulle, C. Nore, Role of boundary conditions in helicoidal flow collimation: Consequences for the von Karman sodium dynamo experiment, (2015) Phys. Rev. E, 92, 063015. This work suggests a new mechanism for the VKS dynamo, where the magnetic field near the blades plays a collimation role on vortices responsible for the alpha-mechanism..

Statistical modelling of large scale structures

[12] R. Monchaux, F. Ravelet, B. Dubrulle, A. Chiffaudel and F. Daviaud, Properties of stationary states in axisymmetric flows, (2006) Phys. Rev. Letters 96 124502 (36 citations). Fist experimental observation of prediction of my statistical theories.

[13] P.-P. Cortet, A. Chiffaudel, F. Daviaud and B. Dubrulle, Experimental evidence of a phase transition in a closed turbulent flow, (2010) Phys. Rev. Lett. 105, 214501. Interpretation of a turbulent bifurcation in term of phase transition.

[14] S. Thalabard, B. Saint-Michel, E. Herbert, F. Daviaud, B. Dubrulle, A statistical mechanics framework for the large-scale structure of turbulent von Karman flows, (2015) NJP,17, 063006. A complete description of the statistical framework to describe large scale structures of a von Karman flow.

[15] M. Mihelich, D. Faranda, D. Paillard, B. Dubrulle, Is Turbulence a State of Maximum Energy Dissipation ?, Entropy 19 (4), 154 (2017). Explores the role of energy dissipation for stationary states.

Quantum turbulence

[16] J. Salort, C. Baudet, B. Castaing, B.Chabaud, F. Daviaud, T. Didelot, P. Diribarne, B. Dubrulle, Y. Gagne, F. Gauthier, A. Girard, B. Hebral, B. Rousset, P. Thibault and P-E. Roche, Turbulent velocity spectra in superfluid flows, (2010) Phys. of Fluids 22 125102.

[17] B. Saint-Michel, E. Herbert, J. Salort, C. Baudet, M. Bon Mardion, P. Bonnay, M. Bourgoin, B. Castaing, L. Chevillard, F. Daviaud, P. Diribarne, B. Dubrulle, Y. Gagne, M. Gibert, A. Girard, B. Hébral, Th. Lehner, B. Rousset, Probing quantum and classical turbulence analogy through global bifurcations in a von Karman liquid Helium experiment, Phys. Fluids 26 (2014) 125109 (1 citations). Proof that dissipation anomaly does not change when going from normal fluid (including Saclay water experiment) to superfluid.

Singularities and Inertial dissipation:

[18] E-W. Saw, D. Kuzzay, D. Faranda, A. Guittonneau, F. Daviaud, C. Wiertel-Gasquet, V. Padilla, B. Dubrulle, Experimental characterization of extreme events of inertial dissipation in a turbulent swirling flow Nature Comm. (2016). This work, performed under my supervision, is the first preliminary attempt to detect possible singularities of turbulence by following through scale the extreme events of inertial dissipation.

[19] D. Kuzzay, E.-W. Saw, J. W. A. Martins, D. Faranda, J.-M. Foucaut, F. Daviaud, B. Dubrulle

New criteria to detect singularities in experimental incompressible flows, Nonlinearity (6) 2381 (2017). Suggests to use the inertial dissipation as a tool to detect singularities or quasi-singularities.

[20] B. Dubrulle, Beyond Kolmogorov cascades, JFM Perspectives (2019). Provides a modern picture of energy transfers in turbulence, connecting quasi-singularities and intermittency through weak formulation of Leray-Duchon-Robert and suggests several prospects associated with this new picture.

Climate Modelling:

[21] C. Herbert, D. Paillard, B. Dubrulle, Vertical Temperature Profiles at Maximum Entropy Production with a Net Exchange Radiative Formulation, (2013) J. Climate 26, 8545-8555. ). Uses principle of entropy maximum to characterize vertical temperature distribution in climate. This work is an improvement of the Paltridge’s work.

[22] C. Herbert , D. Paillard, M. Kageyama, and B. Dubrulle Present and last glacial climates as states of maximum entropy production", Quart. J. of the Roy. Met. Soc. 137  1059-1069 (2011). ). Uses principle of entropy maximum to characterize equilibrium states in climate.

[23] C. Herbert,, D. Paillard, and B. Dubrulle , Entropy production and multiple equilibria, Earth. Sys. Dyn. 2  13-23 (2011). Uses principle of entropy maximum to characterize multiple equilibrium states in climate.