Chargée de recherche à l’Institut de Recherche pour le Développement au CECI

 Internal Tides: Fate, Mixing, and Impact – At the Crossroads of Tools and Disciplines

For the past fifteen years, my research at IRD has focused on internal tides (ITs): their generation, dissipation, interactions with ocean circulation, and their impact on surface properties and biogeochemistry. Generated by the interaction of the barotropic tide with seafloor topography in a stratified ocean, these waves induce large vertical displacements of dense ocean layers, and can often be detected at the surface, particularly through satellite imagery (sunglint, altimetry, SAR).

The dissipation of internal tides fuels diapycnal mixing in the ocean. When it occurs at depth, this mixing supports the global thermohaline circulation; when it occurs near the surface, it can enhance air–sea exchanges and alter biogeochemical properties by bringing cold, nutrient-rich waters to the upper ocean. Quantifying the spatial and temporal distribution of this mixing—key to understanding climate and tracer transport—remains a major scientific challenge. Internal tides encompass a wide range of poorly constrained processes, spanning scales from kilometers to millimeters. They appear as internal wave trains or solitary waves, each with distinct spectral signatures, making them particularly difficult to predict. Their dissipation involves a variety of instability mechanisms, driven by complex interactions with the wave field itself, changes in stratification, and background circulation.

My approach is multi-scale, multi-method, and interdisciplinary, combining idealized and realistic numerical modeling, in-situ observations, and satellite data. I have led two major oceanographic campaigns dedicated to these processes: INDOMIX (2010) in Indonesia, and AMAZOMIX (2021) on the Amazon shelf. I also coordinated the development of several high-resolution regional model configurations (INDO1/4°, INDESO1/12°, AMAZON1/36°, TAPIOCA1/36°), and collaborated with LOPS on idealized models to investigate the effects of wave–eddy interactions.

I am also strongly committed to training through research, supervising co-tutored PhD students, postdoctoral researchers, and many interns, in partnership with universities in Brazil, Indonesia, Benin, Cuba, and Venezuela. Looking ahead, my work aims to deepen our understanding of ITs and their impacts, and to improve their representation in climate models by developing energetically based parameterizations, with the goal of better capturing their role in global climate dynamics.

Jury

Anne-Marie Tréguier	Directrice de Recherche au CNRS, LOPS	Rapporteur
Anne Petrenko	Professeur de l’Université de Marseille, MIO	Rapporteur
Marion Gehlen	Directrice de Recherche, LSCE	Rapporteur
Florent Lyard	Directeur de Recherche, LEGOS	Invité
Isabelle Dadou	Professeur de l’Université de Toulouse, LEGOS	Marraine