Spatial variability of the Arctic Ocean's double-diffusive staircase
Shibley, Nicole C.
Carpenter, Jeffrey R.
Toole, John M.
MetadataShow full item record
The Arctic Ocean thermohaline stratification frequently exhibits a staircase structure overlying the Atlantic Water Layer that can be attributed to the diffusive form of double-diffusive convection. The staircase consists of multiple layers of O(1) m in thickness separated by sharp interfaces, across which temperature and salinity change abruptly. Through a detailed analysis of Ice-Tethered Profiler measurements from 2004 to 2013, the double-diffusive staircase structure is characterized across the entire Arctic Ocean. We demonstrate how the large-scale Arctic Ocean circulation influences the small-scale staircase properties. These staircase properties (layer thicknesses and temperature and salinity jumps across interfaces) are examined in relation to a bulk vertical density ratio spanning the staircase stratification. We show that the Lomonosov Ridge serves as an approximate boundary between regions of low density ratio (approximately 3–4) on the Eurasian side and higher density ratio (approximately 6–7) on the Canadian side. We find that the Eurasian Basin staircase is characterized by fewer, thinner layers than that in the Canadian Basin, although the margins of all basins are characterized by relatively thin layers and the absence of a well-defined staircase. A double-diffusive 4/3 flux law parametrization is used to estimate vertical heat fluxes in the Canadian Basin to be O(0.1) W m−2. It is shown that the 4/3 flux law may not be an appropriate representation of heat fluxes through the Eurasian Basin staircase. Here molecular heat fluxes are estimated to be between O(0.01) and O(0.1) W m−2. However, many uncertainties remain about the exact nature of these fluxes.
Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 980–994, doi:10.1002/2016JC012419.
Suggested CitationJournal of Geophysical Research: Oceans 122 (2017): 980–994
Showing items related by title, author, creator and subject.
Ross, Tetjana; Lavery, Andone C. (American Meteorological Society, 2010-03)The feasibility of using high-frequency acoustic scattering techniques to map the extent and evolution of the diffusive regime of double-diffusive convection in the ocean is explored. A scattering model developed to describe ...
Systematic microstructure variability in double-diffusively stable coastal waters of nonuniform density gradient Duda, Timothy F.; Rehmann, Chris R. (American Geophysical Union, 2002-10-10)Conductivity microstructure, water velocity, and stratification were measured during a tow-yo transect near the New England shelf/slope front in early August 1997. Velocity data were collected with an acoustic Doppler ...
Zhang, Jubao (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1998-08)Double-diffusive processes are studied and parameterized, and their impacts on the oceanic thermohaline circulation are investigated by single-hemisphere numerical models and scaling analysis. Scaling analysis on the ...