Articles | Volume 16, issue 4
Research article 13 Jul 2020
Research article | 13 Jul 2020
The role of turbulence and internal waves in the structure and evolution of a near-field river plume
Rebecca A. McPherson et al.
No articles found.
Craig Stevens, Natalie Robinson, Gabby O'Connor, and Brett Grant
The Cryosphere Discuss.,
Revised manuscript under review for TCShort summary
Along Antarctica's coastal margin melting ice shelves create plumes of very cold sea water. In some circumstances the water is so cold that ice crystals exist in suspension. We present evidence from near the McMurdo Ice Shelf of ice crystals far larger than normal (by an order of magnitude or more). The crystal behaviour is examined by combining measurements of the crystal motion with ocean flow and turbulence data. This helps us make links between ice shelf melting and sea ice formation.
Seung-Tae Yoon, Won Sang Lee, Craig Stevens, Stefan Jendersie, SungHyun Nam, Sukyoung Yun, Chung Yeon Hwang, Gwang Il Jang, and Jiyeon Lee
Ocean Sci., 16, 373–388,Short summary
We investigated the variability in high-salinity shelf water (HSSW) formation in the Terra Nova Bay polynya using hydrographic data from instrumented moorings and vessel-based profiles. We show that HSSW can be formed in the upper water column of the eastern Terra Nova Bay via polynya activity and convective processes, as well as how the nature of circulation in Terra Nova Bay influences HSSW production. This article also discusses the present results in the context of previous analyses.
Craig L. Stevens
Ocean Sci., 14, 801–812,Short summary
Mixing in the ocean is highly variable and it is often difficult to measure the more energetic regions. Here we present the first full-depth turbulence profiles from Cook Strait, New Zealand. This 22 km wide channel between the major islands of New Zealand sustains very fast tidally driven flows. The measurements show that large vertical eddies exist, moving water up and down. This will affect stratification, as well as any biology, as it passes through the strait.
Miles G. McPhee, Craig L. Stevens, Inga J. Smith, and Natalie J. Robinson
Ocean Sci., 12, 507–515,Short summary
Measurements of turbulent heat fluxes in tidally modulated flow of supercool seawater under Antarctic land-fast sea ice show that turbulent heat exchange at the ocean–ice boundary is characterized by the product of friction velocity and (negative) water temperature departure from freezing. Also, the conditions cause platelet ice growth to form on the underside of the sea ice which increases the hydraulic roughness (drag) of fast ice compared to ice without platelets.
C. L. Stevens, P. Sirguey, G. H. Leonard, and T. G. Haskell
The Cryosphere, 7, 1333–1337,
Fong, D. A. and Geyer, W. R.: The alongshore transport of freshwater in a surface-trapped river plume, J. Phys. Oceanogr., 32, 957–972, https://doi.org/10.1175/1520-0485(2002)032<0957:TATOFI>2.0.CO;2, 2002. a
Klymak, J. M. and Gregg, M. C.: Tidally generated turbulence over the Knight Inlet Sill, J. Phys. Oceanogr., 34, 1135–1151, https://doi.org/10.1175/1520-0485(2004)034<1135:TGTOTK>2.0.CO;2, 2004. a
Lueck, R. G., Wolk, F., and Black, K.: Measuring tidal channel turbulence with a vertical microstructure profiler (VMP), RSI Technical Note, TN-026, 1–35, 2013. a
Pickard, G. L. and Stanton, B. R.: Pacific fjords – A review of their water characteristics, in: Fjord Oceanography, edited by: Freeland, H. J., Farmer, D. M., and Levings, C. D., NATO Conference Series (IV Marine Sciences), Springer, Boston, MA, 4, 1–51, https://doi.org/10.1007/978-1-4613-3105-6_1, 1980. a
Weber, L. J.: The hydraulics of open channel flow: An introduction, J. Hydraul. Eng., 127, 246–247, https://doi.org/10.1061/(ASCE)0733-9429(2001)127:3(246), 2001. a, b
River plume characteristics (density, velocity, turbulence) are measured in the first several kilometers of a river flow entering a New Zealand fjord. These observations are used to quantify the influence of the main plume dynamics on controlling the behavior and structure of the flow. The mixing of dense, stationary water from below into the fast-flowing plume drove its deceleration. Internal waves were capable of transporting almost 15 % of the total momentum out beyond the plume's boundaries.
River plume characteristics (density, velocity, turbulence) are measured in the first several...