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Accueil > Équipes > Equipe MEIGE : Modélisation, Expériences et Instrumentation pour la Géophysique et l’Environnement > Diffusion scientifique > Séminaires internes

Internal waves measurements above Great Meteor seamount : turbulence and mixing

Louis Gostiaux 05/01/2012

Turbulent vertical eddy diffusivity (K_z) and dissipation rate (\epsilon) are estimated between 0.5 and 50 m above the sloping side of Great Meteor Seamount, Canary Basin, using 101 moored temperature sensors, 1-mK precision, sampling at 1 Hz. Effectively, detailed observed time-depth temperature images are split in two : a statically stable and a turbulence image. Tides dominate the temperature variations, but the local bottom slope is sub-critical to semidiurnal frequencies. Averaged over a fortnight, the observed overall time-depth mean K_z = 3\pm1\times10^{-3}m^2/s and \epsilon=1.5\pm0.7\times10^{-7}W/kg. Variations with time and depth are large, by up to four orders of magnitude.