Focusing of internal tides by near-inertial waves Cuypers, Y. Bouruet-Aubertot, P. /Vialard, Jérôme McPhaden, M. J. The refraction of internal waves by lower-frequency near-inertial waves has been predicted theoretically, but never observed before. Here, we report observations of semi-diurnal internal tides generated by the rough topography of the Central Indian Ridge, in the presence of a strong, lower-frequency near-inertial wave field generated by a tropical storm. The semi-diurnal internal tide energy is trapped within upward propagating bands with a periodicity close to the inertial period. A ray-tracing model suggests that this trapping results from the internal tide refraction by the shear associated with near-inertial waves. This yields a strong increase of the internal tide energy and shear in space-time regions where the background flow focuses the rays, leading to the formation of caustics. This mechanism may increase vertical mixing generated by baroclinic tides in the vicinity of mid-ocean ridges in tropical regions. 2017 text https://www.documentation.ird.fr/hor/fdi:010069421 fdi:010069421 Cuypers Y., Bouruet-Aubertot P., Vialard Jérôme, McPhaden M. J.. Focusing of internal tides by near-inertial waves. 2017, 44 (5), 2398-2406 EN OCEAN INDIEN ZONE TROPICALE