Observations of turbulent dissipation in the coastal ocean from an autonomous underwater vehicle

The location and intensity of mixing in the world’s oceans is a fundamental topic of modern oceanography, yet the range of dynamical scales in oceanic flows has challenged efforts to quantify when and where dissipation of mechanical energy occurs. Such knowledge is essential to global climate science and prediction. Although global ocean models can resolve some turbulence in the ocean (quasigeostrophic turbulence at scales of O(1-10 km)), they do not resolve the O(1 mm) Kolmogorov scale at which kinetic energy is ultimately dissipated. Even regional ocean models with grid spacing at O(10-100 m) cannot directly resolve this transfer of energy. As such, in situ measurements are still essential to advancing knowledge of mixing, particularly in the coastal ocean. This talk will present high-resolution observations of turbulent dissipation collected in a number of coastal environments using a microstructure-equipped REMUS 600 autonomous underwater vehicle. These observations will be discussed in the context of both the challenges involved in collecting these data and perceived patterns of mixing visible with remote sensing.

Speaker: Nick Nidzieko, UC Santa Barbara