Articles | Volume 16, issue 4
https://doi.org/10.5194/os-16-799-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/os-16-799-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
The role of turbulence and internal waves in the structure and evolution of a near-field river plume
Rebecca A. McPherson
CORRESPONDING AUTHOR
Department of Physics, University of Auckland, Auckland, New Zealand
Craig L. Stevens
Department of Physics, University of Auckland, Auckland, New Zealand
National Institute of Water and Atmospheric Research, Wellington, New Zealand
Joanne M. O'Callaghan
National Institute of Water and Atmospheric Research, Wellington, New Zealand
Andrew J. Lucas
Scripps Institution of Oceanography, University of California San Diego, San Diego, California, USA
Jonathan D. Nash
College of Earth, Oceans and Atmospheric Sciences, Oregon State University, Corvallis, Oregon, USA
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Cited articles
Bowman, M., Dietrich, D., and Mladenov, P.: Predictions of circulation and mixing in Doubtful Sound, arising from variations in runoff and discharge from the Manapouri power station, Coast. Estuar. Stud., 56, 59–76, https://doi.org/10.1029/CE056, 1999. a, b
Chen, F. and MacDonald, D. G.: Role of mixing in the structure and evolution of a buoyant discharge plume, J. Geophys. Res., 111, C11002, https://doi.org/10.1029/2006JC003563, 2006. a
Chen, F., MacDonald, D. G., and Hetland, R. D.: Lateral spreading of a near-field river plume: Observations and numerical simulations, J. Geophys. Res., 114, C07013, https://doi.org/10.1029/2008JC004893, 2009. a
Cummins, P. F., Armi, L., and Vagle, S.: Upstream internal hydraulic jumps, J. Phys. Oceanogr., 36, 753–769, https://doi.org/10.1175/JPO2894.1, 2006. a
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
Garrett, C. and Munk, W.: Space-Time scales of internal waves, Geophysical Fluid Dynamics, 3, 225–264, https://doi.org/10.1080/03091927208236082, 1972. a
Geyer, W. R., Ralston, D. K., and Holleman, R. C.: Hydraulics and mixing in a laterally divergent channel of a highly stratified estuary, J. Geophys. Res.-Oceans, 122, 4743–4760, https://doi.org/10.1002/2016JC012455, 2017. a
Hetland, R. D.: Relating river plume structure to vertical mixing, J. Phys. Oceanogr., 35, 1667–1688, https://doi.org/10.1175/JPO2774.1, 2005. a, b
Hetland, R. D.: The effects of mixing and spreading on density in near-field river plumes, Dynam. Atmos. Oceans, 49, 37–53, https://doi.org/10.1016/j.dynatmoce.2008.11.003, 2010. a, b, c
Honegger, D. A., Haller, M. C., Geyer, W. R., and Farquharson, G.: Oblique internal hydraulic jumps at a stratified estuary mouth, J. Phys. Oceanogr., 47, 85–100, https://doi.org/10.1175/JPO-D-15-0234.1, 2017. a
Hunter, E. J., Chant, R. J., Wilkin, J. L., and Kohut, J.: High-frequency forcing and subtidal response of the Hudson River plume, J. Geophys. Res., 115, C07012, https://doi.org/10.1029/2009JC005620, 2010. a
Jay, D. A., Pan, J., Orton, P. M., and Horner-Devine, A. R.: Asymmetry of Columbia River tidal plume fronts, J. Marine Syst., 78, 442–459, https://doi.org/10.1016/j.jmarsys.2008.11.015, 2009. a, b
Kakoulaki, G., MacDonald, D., and Horner-Devine, A. R.: The role of wind in the near field and midfield of a river plume, Geophys. Res. Lett., 41, 5132–5138, https://doi.org/10.1002/2014GL060606, 2014. a
Kilcher, L. F. and Nash, J. D.: Structure and dynamics of the Columbia River tidal plume front, J. Geophys. Res., 115, C05S90, https://doi.org/10.1029/2009JC006066, 2010. a, b, c
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
MacDonald, D. G. and Chen, F.: Enhancement of turbulence through lateral spreading in a stratified-shear flow: Development and assessment of a conceptual model, J. Geophys. Res., 117, C05025, https://doi.org/10.1029/2011JC007484, 2012. a, b
MacDonald, D. G. and Horner-Devine, A. R.: Temporal and spatial variability of vertical salt flux in a highly stratified estuary, J. Geophys. Res., 113, C09022, https://doi.org/10.1029/2007JC004620, 2008. a
MacDonald, D. G., Goodman, L., and Hetland, R. D.: Turbulent dissipation in a near-field river plume: A comparison of control volume and microstructure observations with a numerical model, J. Geophys. Res., 112, C07026, https://doi.org/10.1029/2006JC004075, 2007. a, b, c, d
MacDonald, D. G., Carlson, J., and Goodman, L.: On the heterogeneity of stratified-shear turbulence: Observations from a near-field river plume, J. Geophys. Res.-Oceans, 118, 6223–6237, https://doi.org/10.1002/2013JC008891, 2013. a, b
McCabe, R. M., Hickey, B. M., and MacCready, P.: Observational estimates of entrainment and vertical salt flux in the interior of a spreading river plume, J. Geophys. Res., 113, C08027, https://doi.org/10.1029/2007JC004361, 2008. a, b
McPherson, R. A., Stevens, C. L., O'Callaghan, J. M., Lucas, A., and Nash, J.: Hydrographic data from near-field Doubtful Sound, New Zealand, SEANOE, https://doi.org/10.17882/74747, 2020. a
Nash, J. D. and Moum, J. N.: Internal hydraulic flows on the continental shelf: High drag states over a small bank, J. Geophys. Res., 106, 4593–4611, https://doi.org/10.1029/1999JC000183, 2001. a, b
Nash, J. D. and Moum, J. N.: River plumes as a source of large-amplitude internal waves in the coastal ocean, Nature, 437, 400–403, https://doi.org/10.1038/nature03936, 2005. a, b, c, d
O'Donnell, J., Ackleson, S. G., and Levine, E. R.: On the spatial scales of a river plume, J. Geophys. Res., 113, C04017, https://doi.org/10.1029/2007JC004440, 2008. a, b
Pan, J. and Jay, D. A.: Dynamic characteristics and horizontal transports of internal solitons generated at the Columbia River plume front, Cont. Shelf Res., 29, 252–262, https://doi.org/10.1016/j.csr.2008.01.002, 2009. a, b, c, d
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
Pawlowicz, R., Beardsley, B., and Lentz, S.: Classical tidal harmonic analysis including error estimates in MATLAB using T_TIDE, Comput. Geosci., 28, 929–937, https://doi.org/10.1016/S0098-3004(02)00013-4, 2002. a
Pritchard, D. W.: Estuarine Hydrography, Adv. Geophys., 1, 243–280, https://doi.org/10.1016/S0065-2687(08)60208-3, 1952. a
Tedford, E. W., Carpenter, J. R., Pawlowicz, R., Pieters, R., and Lawrence, G. A.: Observation and analysis of shear instability in the Fraser River estuary, J. Geophys. Res., 114, C11006, https://doi.org/10.1029/2009JC005313, 2009. a, b
Walters, R. A., Goring, D. G., and Bell, R. G.: Ocean tides around New Zealand, New Zeal. J. Mar. Fresh., 35, 567–579, https://doi.org/10.1080/00288330.2001.9517023, 2001. 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
Yankovsky, A. E., Hickey, B. M., and Münchow, A. K.: Impact of variable inflow on the dynamics of a coastal buoyant plume, J. Geophys. Res., 106, 19809–19824, https://doi.org/10.1029/2001JC000792, 2001. a
Short summary
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...