Estimating dissipation rates associated with double diffusion
Fine, Elizabeth C.
MacKinnon, Jennifer A.
Alford, Matthew H.
Taylor, John R.
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Double diffusion refers to a variety of turbulent processes in which potential energy is released into kinetic energy, made possible in the ocean by the difference in molecular diffusivities between salinity and temperature. Here, we present a new method for estimating the kinetic energy dissipation rates forced by double-diffusive convection using temperature and salinity data alone. The method estimates the up-gradient diapycnal buoyancy flux associated with double diffusion, which is hypothesized to balance the dissipation rate. To calculate the temperature and salinity gradients on small scales we apply a canonical scaling for compensated thermohaline variance (or ‘spice’) on sub-measurement scales with a fixed buoyancy gradient. Our predicted dissipation rates compare favorably with microstructure measurements collected in the Chukchi Sea. Fine et al. (2018), https://doi.org/10.1175/jpo-d-18-0028.1, showed that dissipation rates provide good estimates for heat fluxes in this region. Finally, we show the method maintains predictive skill when applied to a sub-sampling of the Conductivity, Temperature, Depth (CTD) data.
Author Posting. © American Geophysical Union, 2021. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 48(15), (2021): e2021GL092779, https://doi.org/10.1029/2021GL092779.
Suggested CitationMiddleton, L., Fine, E. C., MacKinnon, J. A., Alford, M. H., & Taylor, J. R. (2021). Estimating dissipation rates associated with double diffusion. Geophysical Research Letters, 48(15), e2021GL092779.
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