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Turbulence Scaling Comparisons in the Ocean Surface Boundary Layer
Author(s) -
Esters L.,
Breivik Ø.,
Landwehr S.,
ten Doeschate A.,
Sutherland G.,
Christensen K. H.,
Bidlot J.R.,
Ward B.
Publication year - 2018
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2017jc013525
Subject(s) - scaling , mixed layer , dissipation , turbulence , boundary layer , breaking wave , forcing (mathematics) , buoyancy , turbulence kinetic energy , pelagic zone , mixing (physics) , meteorology , convection , flux (metallurgy) , irradiance , mechanics , atmospheric sciences , physics , geology , oceanography , materials science , wave propagation , thermodynamics , optics , geometry , mathematics , quantum mechanics , metallurgy
Abstract Direct observations of the dissipation rate of turbulent kinetic energy, ϵ , under open ocean conditions are limited. Consequently, our understanding of what chiefly controls dissipation in the open ocean, and its functional form with depth, is poorly constrained. In this study, we report direct open ocean measurements of ϵ from the Air‐Sea Interaction Profiler (ASIP) collected during five different cruises in the Atlantic Ocean. We then combine these data with ocean‐atmosphere flux measurements and wave information in order to evaluate existing turbulence scaling theories under a diverse set of open ocean conditions. Our results do not support the presence of a “breaking” or a “transition layer,” which has been previously suggested. Instead, ϵ decays as | z | − 1.29over the depth interval, which was previously defined as “transition layer,” and as | z | − 1.15over the mixing layer. This depth dependency does not significantly vary between nonbreaking or breaking wave conditions. A scaling relationship based on the friction velocity, the wave age, and the significant wave height describes the observations best for daytime conditions. For conditions during which convection is important, it is necessary to take buoyancy forcing into account.