Articles | Volume 17, issue 5
https://doi.org/10.5194/os-17-1285-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/os-17-1285-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
27 Sep 2021
Research article |
| 27 Sep 2021
| 27 Sep 2021
In situ observations of turbulent ship wakes and their spatiotemporal extent
Amanda T. Nylund
Department of Mechanics and Maritime Sciences, Chalmers University of
Technology, Gothenburg, 412 96 Gothenburg, Sweden
Lars Arneborg
Department of Research and Development, Swedish Meteorological and Hydrological Institute (SMHI), Gothenburg,
426 71 Västra Frölunda, Sweden
Anders Tengberg
Department of Mechanics and Maritime Sciences, Chalmers University of
Technology, Gothenburg, 412 96 Gothenburg, Sweden
Ulf Mallast
Department Monitoring and Exploration Technologies, Helmholtz Centre
for Environmental Research, 04318 Leipzig, Germany
Department of Mechanics and Maritime Sciences, Chalmers University of
Technology, Gothenburg, 412 96 Gothenburg, Sweden
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Cited articles
Andersson, L. and Rydberg, L.: Exchange of water and nutrients between the
Skagerrak and the Kattegat, Estuar. Coast. Shelf Sci., 36, 159–181,
https://doi.org/10.1006/ecss.1993.1011, 1993.
Arneborg, L.: Mixing efficiencies in patchy turbulence, J. Phys. Oceanogr.,
32, 1496–1506, https://doi.org/10.1175/1520-0485(2002)032<1496:MEIPT>2.0.CO;2, 2002.
Arneborg, L., Nylund, A., and
Hassellöv, I-M.: ADCP Gothenburg 2018, Zenodo [data set], https://doi.org/10.5281/zenodo.5066997, 2021.
Balcombe, P., Brierley, J., Lewis, C., Skatvedt, L., Speirs, J., Hawkes, A.,
and Staffell, I.: How to decarbonise international shipping: Options for
fuels, technologies and policies, Energ. Convers. Manage., 182, 72–88,
https://doi.org/10.1016/j.enconman.2018.12.080, 2019.
Barsi, J. A., Barker, J. L., and Schott, J. R.: An Atmospheric Correction
Parameter Calculator for a single thermal band earth-sensing instrument,
IGARSS 2003, 2003 IEEE International Geoscience and Remote Sensing
Symposium, Proceedings (IEEE Cat. No. 03CH37477), Centre de Congress Pierre
Bandis, Toulouse, France, 21–25 July, 2003.
Bickel, S. L., Malloy Hammond, J. D., and Tang, K. W.: Boat-generated
turbulence as a potential source of mortality among copepods, J. Exp. Mar.
Biol. Ecol., 401, 105–109, https://doi.org/10.1016/j.jembe.2011.02.038, 2011.
Buhaug, Ø., Corbett, J., Endresen, Ø., Eyring, V., Faber, J.,
Hanayama, S., Lee, D. S., Lee, D., Lindstad, H., Markowska, A. Z., Mjelde,
A., Nelissen, D., Nilsen, J., Pålsson, C., Winebrake, J., Wu, W., and
Yoshida, K.: Second IMO GHG study 2009, International Maritime Organisation
(IMO), London, 2009.
Carrica, P. M., Drew, D., Bonetto, F., and Lahey, R. T.: A polydisperse
model for bubbly two-phase flow around a surface ship, Int. J. Multiphase
Flow, 25, 257–305, https://doi.org/10.1016/S0301-9322(98)00047-0, 1999.
Emerson, S. and Bushinsky, S.: The role of bubbles during air-sea gas
exchange, J. Geophys. Res.-Ocean., 121, 4360–4376, https://doi.org/10.1002/2016jc011744, 2016.
Ermakov, S. A. and Kapustin, I. A.: Experimental study of turbulent-wake
expansion from a surface ship, Izv, Atmos. Ocean. Phys., 46, 524–529,
https://doi.org/10.1134/S0001433810040110, 2010.
Foga, S., Scaramuzza, P. L., Guo, S., Zhu, Z., Dilley, R. D., Beckmann, T.,
Schmidt, G. L., Dwyer, J. L., Joseph Hughes, M., and Laue, B.: Cloud
detection algorithm comparison and validation for operational Landsat data
products, Remote Sens. Environ., 194, 379–390, https://doi.org/10.1016/j.rse.2017.03.026, 2017.
Francisco, F., Carpman, N., Dolguntseva, I., and Sundberg, J.: Use of
Multibeam and Dual-Beam Sonar Systems to Observe Cavitating Flow Produced by
Ferryboats: In a Marine Renewable Energy Perspective, J. Mar. Sci. Eng., 5,
30, https://doi.org/10.3390/jmse5030030, 2017.
Fu, H. and Wan, P.: Numerical simulation on ship bubbly wake, J.
Mar. Sci. Appl., 10, 413–418, https://doi.org/10.1007/s11804-011-1086-x, 2011.
Fujimura, A., Soloviev, A., Rhee, S. H., and Romeiser, R.: Coupled Model
Simulation of Wind Stress Effect on Far Wakes of Ships in SAR Images, IEEE
T. Geosci. Remote, 54, 2543–2551, https://doi.org/10.1109/TGRS.2015.2502940, 2016.
Garrison, H. S. and Tang, K. W.: Effects of episodic turbulence on diatom
mortality and physiology, with a protocol for the use of Evans Blue stain
for live–dead determinations, Hydrobiologia, 738, 155–170, https://doi.org/10.1007/s10750-014-1927-0, 2014.
Gilman, M., Soloviev, A., and Graber, H.: Study of the far wake of a large
ship, J. Atmos. Ocean. Tech., 28, 720–733, https://doi.org/10.1175/2010JTECHO791.1, 2011.
Golbraikh, E. and Beegle-Krause, C.: A model for the estimation of the
mixing zone behind large sea vessels, Environ. Sci. Pollut.
Res., 27, 37911–37919, https://doi.org/10.1007/s11356-020-09890-y, 2020.
Hassellöv, I., Larsson, K., and Sundblad, E.: Effekter på
havsmiljön av att flytta över godstransporter från vägtrafik
till sjöfart, Rapport nr. 2019, 5, Havsmiljöinstitutet, 2019.
Heiselberg, H.: A direct and fast methodology for ship recognition in
Sentinel-2 multispectral imagery, Remote Sens., 8, 1033, https://doi.org/10.3390/rs8121033, 2016.
HELCOM: Maritime Activities in the Baltic Sea – An Integrated Thematic
Assessment on Maritime Activities and Response to Pollution at Sea in the
Baltic Sea Region, Balt, Sea Environ. Proc. No. 123, Helsinki Commission
(HELCOM), Helsinki, Finland, 65 pp., 2010.
HELCOM: Assessment on maritime activities in the 25 Baltic Sea 2018, Baltic Sea Environment Proceedings No. 152, Helsinki Commission, Helsinki, Finland, 253 pp., 2018.
Issa, V. and Daya, Z. A.: Modeling the turbulent trailing ship wake in the
infrared, Appl. Opt., 53, 4282–4296, https://doi.org/10.1364/AO.53.004282, 2014.
Jakobsson, M., Stranne, C., O'Regan, M., Greenwood, S. L., Gustafsson, B.,
Humborg, C., and Weidner, E.: Bathymetric properties of the Baltic Sea,
Ocean Sci., 15, 905–924, https://doi.org/10.5194/os-15-905-2019, 2019.
Jalkanen, J.-P., Johansson, L., and Kukkonen, J.: A Comprehensive Inventory
of the Ship Traffic Exhaust Emissions in the Baltic Sea from 2006 to 2009,
Ambio, 43, 311–324, https://10.1007/s13280-013-0389-3, 2014.
Karlson, B., Andersson, L., Kaitala, S., Kronsell, J., Mohlin, M.,
Seppälä, J., and Wranne, A. W.: A comparison of Ferrybox data vs.
monitoring data from research vessels for near surface waters of the Baltic
Sea and the Kattegat, J. Mar. Syst., 162, 98–111, https://doi.org/10.1016/j.jmarsys.2016.05.002, 2016.
Kato, H. and Phillips, O.: On the penetration of a turbulent layer into
stratified fluid, J. Fluid Mech., 37, 643–655, https://doi.org/10.1017/S0022112069000784, 1969.
Katz, C. N., Chadwick, D. B., Rohr, J., Hyman, M., and Ondercin, D.: Field
measurements and modeling of dilution in the wake of a US navy frigate, Mar.
Pollut. Bull., 46, 991–1005, https://doi.org/10.1016/S0025-326X(03)00117-6, 2003.
Leppäranta, M. and Myrberg, K.: Physical oceanography of the Baltic
Sea, Springer-Verlag Berlin Heidelberg, Germany, 378 pp., 2009.
Liefvendahl, M. and Wikström, N.: Modelling and simulation of surface ship wake signatures, Report FOI-R-4344-SE, Swedish Defence Research Agency (FOI), Stockholm, 36 pp., 2018.
Loehr, L., Mearns, A., and George, K.: Cruise Ship Wastewater Science Advisory Panel, initial report on the 10 July 2011 study of opportunity: currents and wake turbulence behind cruise ships, Alaska Department of Environmental Conservation. Division of Water, Juneau, Alaska. 21 pp., 2001.
Loehr, L. C., Beegle-Krause, C.-J., George, K., McGee, C. D., Mearns, A. J.,
and Atkinson, M. J.: The significance of dilution in evaluating possible
impacts of wastewater discharges from large cruise ships, Mar. Pollut.
Bull., 52, 681–688, https://doi.org/10.1016/j.marpolbul.2005.10.021, 2006.
Lucas, N., Simpson, J., Rippeth, T., and Old, C.: Measuring turbulent
dissipation using a tethered ADCP, J. Atmos. Ocean. Tech., 31, 1826–1837,
https://doi.org/10.1175/JTECH-D-13-00198.1, 2014.
Mallast, U. and Siebert, C.: Combining continuous spatial and temporal scales for SGD investigations using UAV-based thermal infrared measurements, Hydrol. Earth Syst. Sci., 23, 1375–1392, https://doi.org/10.5194/hess-23-1375-2019, 2019.
Marmorino, G. and Trump, C.: Preliminary side-scan ADCP measurements across
a ship's wake, J. Atmos. Ocean. Tech., 13, 507–513, https://doi.org/10.1175/1520-0426(1996)013<0507:PSSAMA>2.0.CO;2, 1996.
Moldanová, J., Fridell, E., Matthias, V., Hassellöv, I.-M., Eriksson, M., Jalkanen, J.-P., Tröeltzsch, J., Quante, M., Johansson, L., and Majutenko, I.: Information on completed BONUS SHEBA project, Baltic Marine Environment Protection Commission, Maritime Working Group, MARITIME 18-2018, Hamburg, 80
Germany, 18 pp., 2018.
NDRC: The Physics of Sound in the Sea, United States Office of Scientific
Research and Development, National Defense Research Committee, Division 6,
Washington, D.C., 1946.
Otsu, N.: A Threshold Selection Method from Gray-Level Histograms, IEEE T.
Syst. Man Cyb., 9, 62–66, https://doi.org/10.1109/TSMC.1979.4310076, 1979.
Parmhed, O. and Svennberg, U.: Simulering av luftbubblor och ytvågor
runt ytfartyg, Repot FOI-R-2217-SE, FOI – Swedish Defence Research Agency,
Tumba, 2006.
Petersen, W.: FerryBox systems: State-of-the-art in Europe and future
development, J. Mar. Syst., 140, 4–12, https://doi.org/10.1016/j.jmarsys.2014.07.003, 2014.
Reissmann, J. H., Burchard, H., Feistel, R., Hagen, E., Lass, H. U.,
Mohrholz, V., Nausch, G., Umlauf, L., and Wieczorek, G.: Vertical mixing in
the Baltic Sea and consequences for eutrophication – A review, Prog.
Oceanogr., 82, 47–80, https://doi.org/10.1016/j.pocean.2007.10.004, 2009.
Smirnov, A., Celik, I., and Shi, S.: LES of bubble dynamics in wake flows,
Comput. Fluid., 34, 351–373, https://doi.org/10.1016/j.compfluid.2004.05.004, 2005.
Smith, S. D.: Coefficients for sea surface wind stress, heat flux, and wind
profiles as a function of wind speed and temperature, J. Geophys.
Res.-Ocean., 93, 15467–15472, https://doi.org/10.1029/JC093iC12p15467, 1988.
Smith, T. W., Jalkanen, J., Anderson, B., Corbett, J., Faber, J., Hanayama,
S., O'keeffe, E., Parker, S., Johanasson, L., and Aldous, L.: Third IMO GHG
study 2014, International Maritime Organisation (IMO), London, 2015.
Snoeijs-Leijonmalm, P., and Andrén, E.: Biological oceanography of the
Baltic Sea, Springer Science & Business Media, Dordrecht, the Netherlands,
683 pp., 2017.
Soloviev, A., Gilman, M., Young, K., Brusch, S., and Lehner, S.: Sonar
measurements in ship wakes simultaneous with TerraSAR-X overpasses, IEEE T.
Geosci. Remote, 48, 841–851, https://doi.org/10.1109/TGRS.2009.2032053, 2010.
Soloviev, A., Maingot, C., Agor, M., Nash, L., and Dixon, K.: 3D sonar
measurements in wakes of ships of opportunity, J. Atmos. Ocean. Tech., 29,
880–886, https://doi.org/10.1175/JTECH-D-11-00120.1, 2012.
Soomere, T.: Nonlinear Components of Ship Wake Waves, Appl. Mech. Rev., 60, 120–138,
https://doi.org/10.1115/1.2730847, 2007.
Soomere, T. and Kask, J.: A specific impact of waves of fast ferries on
sediment transport processes of Tallinn Bay, Proc. Estonian Acad. Sci. Biol.
Ecol, 52, 319–331, 2003.
Soomere, T., Parnell, K., and Didenkulova, I.: Implications of fast-ferry
wakes for semi-sheltered beaches: a case study at Aegna Island, Baltic Sea,
J. Coast. Res., SI 56, 128–132, 2009.
Stanic, S., Caruthers, J. W., Goodman, R. R., Kennedy, E., and Brown, R. A.:
Attenuation measurements across surface-ship wakes and computed bubble
distributions and void fractions, IEEE J. Ocean. Eng., 34, 83–92,
https://doi.org/10.1109/JOE.2008.2008411, 2009.
Stigebrandt, A.: Physical oceanography of the Baltic Sea, in: A systems
analysis of the Baltic Sea, Springer, Berlin, Heidelberg, 19–74, 2001.
Sutherland, P. and Melville, W. K.: Field measurements of surface and
near-surface turbulence in the presence of breaking waves, J. Phys.
Oceanogr., 45, 943–965, https://doi.org/10.1175/JPO-D-14-0133.1, 2015.
Swedish Maritime Administration, Nautical Information – Sjofartsverket, available at:
https://www.sjofartsverket.se/en/services/pilotage/pilot-area-gothenburg/nautical-information/ (last access: 31 August 2021), 2020.
The Port of Gothenburg: Expand your business. Call the gateway to Scandinavia, available at: https://www.portofgothenburg.com/FileDownload/?contentReferenceID=12900, 9 pp., last access: 18 May 2020.
Thorpe, S. A.: An introduction to ocean turbulence, Cambridge University
Press, New York, 240 pp., 2007.
Trevorrow, M. V., Vagle, S., and Farmer, D. M.: Acoustical measurements of
microbubbles within ship wakes, J. Acoust. Soc. Am., 95, 1922–1930,
https://doi.org/10.1121/1.408706, 1994.
UNCTAD: Review of Maritime Transport 2019, UNCTAD/RMT/2019, United Nations
Publications, New York, 2019.
US-EPA: Cruise Ship Plume Tracking Survey Report, U.S. Environmental
Protection Agency, Washington, D.C., 2002.
van der Lee, E. M. and Umlauf, L.: Internal wave mixing in the Baltic Sea: Near-inertial waves in the absence of tides, J. Geophys. Res., 116, C10016, https://doi.org/10.1029/2011jc007072,
2011.
Vollmer, M.: Newton's law of cooling revisited, Eur. J. Phys., 30, 1063, https://doi.org/10.1088/0143-0807/30/5/014, 2009.
Voropayev, S., Nath, C., and Fernando, H.: Thermal surface signatures of
ship propeller wakes in stratified waters, Phys. Fluids, 24, 116603,
https://doi.org/10.1063/1.4767130, 2012.
Weber, T. C., Lyons, A. P., and Bradley, D. L.: An estimate of
the gas transfer rate from oceanic bubbles derived from multibeam
sonar observations of a ship wake, J. Geophys. Res., 110, C04005,
https://doi.org/10.1029/2004JC002666, 2005.
Xu, H.: Modification of normalised difference water index (NDWI) to enhance
open water features in remotely sensed imagery, Int. J. Remote Sens., 27,
3025–3033, https://doi.org/10.1080/01431160600589179, 2006.
Short summary
Acoustic and satellite observations of turbulent ship wakes show that ships can mix the water column down to 30 m depth and that a temperature signature of the wake can last for tens of kilometres after ship passage. Turbulent wakes deeper than 12 m were frequently detected, which is deeper than previously reported. The observed extent of turbulent ship wakes implies that in areas with intensive ship traffic, ship mixing should be considered when assessing environmental impacts from shipping.
Acoustic and satellite observations of turbulent ship wakes show that ships can mix the water...
