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Three-dimensionality of shallow island wakes

  • Paul M. BransonEmail author
  • Marco Ghisalberti
  • Gregory N. Ivey
Original Article

Abstract

Island wakes are thought to play a significant role in the vertical and cross-shelf mixing processes in strong tidally forced coastal regions. This paper describes a comprehensive laboratory study of shallow water wakes behind islands of circular cross section forced by a sinusoidal tidal flow. The wake structure and vertical circulation are determined through novel three-dimensional particle imaging velocimetry measurements. Four archetypal wake forms (symmetric, asymmetric, unsteady bubble, and vortex shedding) are observed. Through examination of the vertical structure of each of these wake forms, we demonstrate the dependence of vertical transport in island wakes on three key parameters: (1) the tidal excursion relative to the island size, (2) the bottom boundary layer thickness relative to the flow depth and (3) the aspect ratio of the island size to the flow depth. The importance of secondary vortices in island upwelling is highlighted by local peaks in vertical velocity that exceed 40% of the peak external tidal velocity. This study fundamentally changes the view of island wake upwelling from a weak ‘tea cup’-like recirculation process to one where primary and secondary flow structures vigorously stir the water column over the full depth. This has fundamental implications for the fate of passive biological tracers and the time scales that determine productivity in topographically-complex continental shelf regions.

Keywords

Island wakes Three dimensional flow Tidal forcing Upwelling Vorticity 

Notes

Acknowledgements

P. M. Branson gratefully acknowledges the support of a University Club of Western Australia Research Travel Scholarship to attend the 4th International Symposium on Shallow Flows. The authors acknowledge numerous insightful discussions with E. J. Hopfinger during his visit to UWA on a Gledden Visiting Fellowship. This work was supported by resources provided by the Pawsey Supercomputing Centre with funding from the Australian Government and the Government of Western Australia. We acknowledge the use of imagery provided by services from the Global Imagery Browse Services (GIBS), operated by the NASA/Goddard Space Flight Center Earth Science Data and Information System (ESDIS) project. Funding was provided by Australian Research Council Discovery Project (Grant No. DP1095294).

References

  1. 1.
    Akilli H, Rockwell D (2002) Vortex formation from a cylinder in shallow water. Phys Fluids 14(9):2957–2967.  https://doi.org/10.1063/1.1483307 CrossRefGoogle Scholar
  2. 2.
    Akkermans RAD, Kamp LPJ, Clercx HJH, van Heijst GJF (2008) Intrinsic three-dimensionality in electromagnetically driven shallow flows. Europhys Lett 83(2):24001.  https://doi.org/10.1209/0295-5075/83/24001 CrossRefGoogle Scholar
  3. 3.
    Atkinson C, Coudert S, Foucaut JM, Stanislas M, Soria J (2011) The accuracy of tomographic particle image velocimetry for measurements of a turbulent boundary layer. Exp Fluids 50(4):1031–1056.  https://doi.org/10.1007/s00348-010-1004-z CrossRefGoogle Scholar
  4. 4.
    Batchelor G (1967) An introduction to fluid dynamics. Cambridge University Press, Cambridge, Cambridge Mathematical Library.  https://doi.org/10.1017/cbo9780511800955 Google Scholar
  5. 5.
    Belden J (2013) Calibration of multi-camera systems with refractive interfaces. Exp Fluids 54(2):1–18.  https://doi.org/10.1007/s00348-013-1463-0 CrossRefGoogle Scholar
  6. 6.
    Belden J, Truscott TT, Axiak MC, Techet AH (2010) Three-dimensional synthetic aperture particle image velocimetry. Meas Sci Technol 21(12):125403.  https://doi.org/10.1088/0957-0233/21/12/125403 CrossRefGoogle Scholar
  7. 7.
    Branson PM, Ghisalberti M, Ivey GN (2016) Time resolved 3D3C measurements of shallow-water island wakes. In: Ivey GN, Jones NL, Zhou T (eds) Proceedings of the 20th Australasian Fluid Mechanics Conference, Conference Paper 526, 2016Google Scholar
  8. 8.
    Branson PM, Ghisalberti M, Ivey GN, Hopfinger EJ (2019) Cylinder wakes in shallow oscillatory flow: the coastal island wake problem. J Fluid Mech. https://arxiv.org/abs/1902.00222
  9. 9.
    Chen D, Jirka GH (1995) Experimental study of plane turbulent wakes in a shallow water layer. Fluid Dyn Res 16(1):11–41.  https://doi.org/10.1016/0169-5983(95)00053-g CrossRefGoogle Scholar
  10. 10.
    Chopra K, Hubert L (1965) Mesoscale eddies in wake of islands. J Atmos Sci 22(6):652–657. https://doi.org/10.1175/1520-0469(1965)022<0652:MEIWOI>2.0.CO;2CrossRefGoogle Scholar
  11. 11.
    Chu V, Wu J, Khayat R (1983) Stability of turbulent shear flows in shallow channel. In: Proceedings of the 20th Congress of IAHR, Moscow, vol 3, pp 128–133Google Scholar
  12. 12.
    Duran-Matute M, Kamp LPJ, Trieling RR, van Heijst GJF (2012) Regimes of two-dimensionality of decaying shallow axisymmetric swirl flows with background rotation. J Fluid Mech 691:214CrossRefGoogle Scholar
  13. 13.
    Earl TA, Paetzold J, Cochard S (2013) Tomographic PIV measurements of turbulent fountains with refraction index matching. J Flow Vis Image Process.  https://doi.org/10.1615/jflowvisimageproc.2014011727 Google Scholar
  14. 14.
    Hoitink A (2004) Tidally-induced clouds of suspended sediment connected to shallow-water coral reefs. Mar Geol 208(1):13–31.  https://doi.org/10.1016/j.margeo.2004.04.021 CrossRefGoogle Scholar
  15. 15.
    Ingram RG, Chu VH (1987) Flow around islands in Rupert Bay: an investigation of the bottom friction effect. J Geophys Res 92(C13):14521–14533.  https://doi.org/10.1029/jc092ic13p14521 CrossRefGoogle Scholar
  16. 16.
    Jenner K, Jenner M, McCabe K (2001) Geographical and temporal movements of humpback whales in Western Australian waters. APPEA J 38(1):692–707.  https://doi.org/10.1071/aj00044 Google Scholar
  17. 17.
    Johnston DW, Read AJ (2007) Flow-field observations of a tidally driven island wake used by marine mammals in the Bay of Fundy, Canada. Fish Oceanogr 16(5):422–435.  https://doi.org/10.1111/j.1365-2419.2007.00444.x CrossRefGoogle Scholar
  18. 18.
    Kamp LPJ (2012) Strain–vorticity induced secondary motion in shallow flows. Phys Fluids 24(2):023601.  https://doi.org/10.1063/1.3682097 CrossRefGoogle Scholar
  19. 19.
    Keane RD, Adrian RJ (1992) Theory of cross-correlation analysis of PIV images. Appl Sci Res 49(3):191–215.  https://doi.org/10.1007/bf00384623 CrossRefGoogle Scholar
  20. 20.
    Lloyd PM, Stansby PK (1997) Shallow-water flow around model conical islands of small side slope. I: surface piercing. J Hydraul Eng 123(12):1057–1067.  https://doi.org/10.1061/(ASCE)0733-9429(1997)123:12(1057) CrossRefGoogle Scholar
  21. 21.
    Lloyd PM, Stansby PK, Chen D (2001) Wake formation around islands in oscillatory laminar shallow-water flows. Part 1. Experimental investigation. J Fluid Mech 429:217–238.  https://doi.org/10.1017/s0022112000002822 CrossRefGoogle Scholar
  22. 22.
    Moffat RJ (1988) Describing the uncertainties in experimental results. Exp Therm Fluid Sci 1(1):3–17.  https://doi.org/10.1016/0894-1777(88)90043-x CrossRefGoogle Scholar
  23. 23.
    Pattiaratchi C, James A, Collins M (1987) Island wakes and headland eddies: a comparison between remotely sensed data and laboratory experiments. J Geophys Res 92(C1):783–794.  https://doi.org/10.1029/jc092ic01p00783 CrossRefGoogle Scholar
  24. 24.
    Raffel M, Willert C, Wereley S (2007) Particle image velocimetry: a practical guide. Springer, BerlinGoogle Scholar
  25. 25.
    Sarpkaya T (1986) Force on a circular cylinder in viscous oscillatory flow at low Keulegan–Carpenter numbers. J Fluid Mech 165:61–71.  https://doi.org/10.1017/s0022112086002999 CrossRefGoogle Scholar
  26. 26.
    Satijn MP, Cense AW, Verzicco R, Clercx HJH, van Heijst GJF (2001) Three-dimensional structure and decay properties of vortices in shallow fluid layers. Phys Fluids 13(7):1932–1945.  https://doi.org/10.1063/1.1374936 CrossRefGoogle Scholar
  27. 27.
    Scarano F, Poelma C (2009) Three-dimensional vorticity patterns of cylinder wakes. Exp Fluids 47(1):69.  https://doi.org/10.1007/s00348-009-0629-2 CrossRefGoogle Scholar
  28. 28.
    Sciacchitano A, Neal DR, Smith BL, Warner SO, Vlachos PP, Wieneke B, Scarano F (2015) Collaborative framework for PIV uncertainty quantification: comparative assessment of methods. Meas Sci Technol 26(7):074004.  https://doi.org/10.1088/0957-0233/26/7/074004 CrossRefGoogle Scholar
  29. 29.
    Signell RP, Geyer WR (1991) Transient eddy formation around headlands. J Geophys Res Oceans 96(C2):2561–2575.  https://doi.org/10.1029/90JC02029 CrossRefGoogle Scholar
  30. 30.
    Van Dyke M (1982) An album of fluid motion. Parabolic Press, Stanford.  https://doi.org/10.1115/1.3241909 Google Scholar
  31. 31.
    Westerweel J (1997) Fundamentals of digital particle image velocimetry. Meas Sci Technol 8(12):1379.  https://doi.org/10.1088/0957-0233/8/12/002 CrossRefGoogle Scholar
  32. 32.
    Westerweel J, Scarano F (2005) Universal outlier detection for PIV data. Exp Fluids 39(6):1096–1100.  https://doi.org/10.1007/s00348-005-0016-6 CrossRefGoogle Scholar
  33. 33.
    Williamson CHK (1985) Sinusoidal flow relative to circular cylinders. J Fluid Mech 155:141–174.  https://doi.org/10.1017/s0022112085001756 CrossRefGoogle Scholar
  34. 34.
    Wolanski E, Hamner W (1988) Topographically controlled fronts in the ocean and their biological influence. Science (New York, NY) 241(4862):177.  https://doi.org/10.1126/science.241.4862.177 CrossRefGoogle Scholar
  35. 35.
    Wolanski E, Imberger J, Heron ML (1984) Island wakes in shallow coastal waters. J Geophys Res 89(C6):10553–10569.  https://doi.org/10.1029/jc089ic06p10553 CrossRefGoogle Scholar
  36. 36.
    Wolanski E, Asaeda T, Tanaka A, Deleersnijder E (1996) Three-dimensional island wakes in the field, laboratory experiments and numerical models. Cont Shelf Res 16(11):1437–1452.  https://doi.org/10.1016/0278-4343(95)00087-9 CrossRefGoogle Scholar
  37. 37.
    Wolanski E, Brinkman R, Spagnol S, McAllister F, Steinberg C, Skirving W, Deleersnijder E, Lakhan V (2003) Merging scales in models of water circulation: perspectives from the Great Barrier Reef. Adv Coast Model 67:411–429.  https://doi.org/10.1016/S0422-9894(03)80132-0 CrossRefGoogle Scholar

Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Oceans Graduate SchoolUniversity of Western AustraliaCrawleyAustralia

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