Vertical mixing at intermediate depths in the Arctic boundary current

• Main Authors: Lenn, YD, Wiles, PJ, Torres-Valdes, S, Abrahamsen, EP, Rippeth, TP, Simpson, JH, Bacon, S, Laxon, SW, Polyakov, I, Ivanov, V, Kirillov, S
• Format: Article in Journal/Newspaper
• Language: English
• Published: AMER GEOPHYSICAL UNION 2009
• Subjects: OCEAN; TURBULENCE; BASIN; FLOW; SEAS; Arctic
• Online Access: https://discovery.ucl.ac.uk/id/eprint/1338045/1/2008GL036792.pdf; https://discovery.ucl.ac.uk/id/eprint/1338045/

Microstructure and hydrographic observations, during September 2007 in the boundary current on the East Siberian continental slope, document upper ocean stratification and along-stream water mass changes. A thin warm surface layer overrides a shallow halocline characterized by a similar to 40-m thick temperature minimum layer beginning at similar to 30 m depth. Below the halocline, well-defined thermohaline diffusive staircases extended downwards to warm Atlantic Water intrusions found at 200-800 m depth. Observed turbulent eddy kinetic energy dissipations are extremely low (epsilon < 10(-6) W m(-3)), such that double diffusive convection dominates the vertical mixing in the upper-ocean. The diffusive convection heat fluxes F-H(dc) similar to 1 W m(-2), are an order of magnitude too small to account for the observed along-stream cooling of the boundary current. Our results implicate circulation patterns and the influence of shelf waters in the evolution of the boundary current waters. Citation: Lenn, Y. D., et al. (2009), Vertical mixing at intermediate depths in the Arctic boundary current, Geophys. Res. Lett., 36, L05601, doi:10.1029/2008GL036792.