Speaker: Nicole Couto (SIO)
Title: Turbulence measurements in Bering Strait
Abstract: Three survey lines were occupied in Bering Strait during the fall of 2015, where high-resolution measurements of temperature, salinity, velocity, and turbulent dissipation rates were collected. These first-ever turbulence measurements in Bering Strait show that dissipation rates here are extremely elevated over global averages, even during calm winds. Measurements of turbulent kinetic energy dissipation rates in the bottom boundary layer were 2-3 orders of magnitude above typical ocean levels. This has important implications for the modification of water properties during transit from the Pacific to the Arctic. We compute a bottom drag coefficient of 1 × 10−3 from a linear regression between our measured dissipation rates and those calculated from near-bottom velocities using the law-of-the-wall formulation. This result is one-third of the value typically used to estimate bottom stress in the region and better predicts transport variability through Bering Strait.