Articles | Volume 18, issue 2
https://doi.org/10.5194/os-18-389-2022
© Author(s) 2022. 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-18-389-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Technical note: Turbulence measurements from a light autonomous underwater vehicle
Geophysical Institute, University of Bergen and Bjerknes Center for Climate Research, Bergen, Norway
Tore Mo-Bjørkelund
Department of Marine Technology, Norwegian University of Science and Technology, Trondheim, Norway
Ilker Fer
Geophysical Institute, University of Bergen and Bjerknes Center for Climate Research, Bergen, Norway
Department of Arctic Geophysics, UNIS – The University Centre in Svalbard, Longyearbyen, Norway
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Cited articles
Dhanak, M. R. and Holappa, K.: An Autonomous Ocean Turbulence
Measurement Platform, J. Atmos. Ocean. Tech., 16,
1506–1518, https://doi.org/10.1175/1520-0426(1999)016<1506:AAOTMP>2.0.CO;2, 1999. a
E.U. Copernicus Marine Service Information: Arctic Ocean – Sea and Ice Surface Temperature,
E.U. Copernicus Marine Service Information [data set], https://doi.org/10.48670/MOI-00130, 2020. a
Fer, I., Peterson, A. K., and Ullgren, J. E.: Microstructure Measurements
from an Underwater Glider in the Turbulent Faroe Bank Channel
Overflow, J. Atmos. Ocean. Tech., 31, 1128–1150,
https://doi.org/10.1175/JTECH-D-13-00221.1, 2014. a, b, c
Fer, I., Mo-Bjørkelund, T., and Kolås, E. H.: Dissipation measurements from
AUV transects across a surface temperature front in the Barents Sea, NMDC [data set],
https://doi.org/10.21335/NMDC-1821443450, 2021. a, b
Fossum, T. O., Norgren, P., Fer, I., Nilsen, F., Koenig, Z. C., and Ludvigsen,
M.: Adaptive Sampling of Surface Fronts in the Arctic Using an Autonomous
Underwater Vehicle, IEEE J. Oceanic Eng., 46, 1155–1164, https://doi.org/10.1109/JOE.2021.3070912, 2021. a
Frajka-Williams, E., Brearley, J. A., Nash, J. D., and Whalen, C. B.: Chapter
14 – New technological frontiers in ocean mixing, in: Ocean Mixing,
edited by: Meredith, M. and Garabato, A. N., 345–361, Elsevier,
https://doi.org/10.1016/B978-0-12-821512-8.00021-9, 2022. a, b
Garabato, A. C. N., Frajka-Williams, E. E., Spingys, C. P., Legg, S., Polzin,
K. L., Forryan, A., Abrahamsen, E. P., Buckingham, C. E., Griffies, S. M.,
McPhail, S. D., Nicholls, K. W., Thomas, L. N., and Meredith, M. P.: Rapid
mixing and exchange of deep-ocean waters in an abyssal boundary current,
P. Natl. Acad. Sci. USA, 116, 13233–13238,
https://doi.org/10.1073/pnas.1904087116, 2019. a
Gregg, M. C.: Ocean Mixing, Cambridge University Press,
https://doi.org/10.1017/9781316795439, 2021. a
Jakobsson, M., Mayer, L. A., Bringensparr, C., Castro, C. F., Mohammad, R.,
Johnson, P., Ketter, T., Accettella, D., Amblas, D., An, L., Arndt, J. E.,
Canals, M., Casamor, J. L., Chauché, N., Coakley, B., Danielson, S.,
Demarte, M., Dickson, M.-L., Dorschel, B., Dowdeswell, J. A., Dreutter, S.,
Fremand, A. C., Gallant, D., Hall, J. K., Hehemann, L., Hodnesdal, H., Hong,
J., Ivaldi, R., Kane, E., Klaucke, I., Krawczyk, D. W., Kristoffersen, Y.,
Kuipers, B. R., Millan, R., Masetti, G., Morlighem, M., Noormets, R.,
Prescott, M. M., Rebesco, M., Rignot, E., Semiletov, I., Tate, A. J.,
Travaglini, P., Velicogna, I., Weatherall, P., Weinrebe, W., Willis, J. K.,
Wood, M., Zarayskaya, Y., Zhang, T., Zimmermann, M., and Zinglersen, K. B.:
The International Bathymetric Chart of the Arctic Ocean Version
4.0, Scientific Data, 7, 176, https://doi.org/10.1038/s41597-020-0520-9, 2020. a
Levine, E. R. and Lueck, R. G.: Turbulence Measurement from an Autonomous
Underwater Vehicle, J. Atmos. Ocean. Tech., 16,
1533–1544, https://doi.org/10.1175/1520-0426(1999)016<1533:TMFAAU>2.0.CO;2, 1999. a, b
Lueck, R. G.: Horizontal and vertical turbulence profilers, in: Marine
Turbulence: Theories, observations and models. Results of the CARTUM
project, edited by: Baumert, H. Z., Simpson, J. H., and Sündermann, J.,
89–100, Cambridge University Press, Cambridge, UK, ISBN 978-05-2115-372-0, 2005. a
Lueck, R. G.: The statistics of turbulence measurements. Part 2: Shear
spectra and a new spectral model, J. Atmos. Ocean.
Tech., in review, 2022. a
Lueck, R. G., Wolk, F., and Yamazaki, H.: Oceanic Velocity Microstructure
Measurements in the 20th Century, J. Oceanogr., 58, 153–174,
https://doi.org/10.1023/A:1015837020019, 2002. a, b, c
McPhail, S., Templeton, R., Pebody, M., Roper, D., and Morrison, R.: Autosub
Long Range AUV Missions Under the Filchner and Ronne Ice
Shelves in the Weddell Sea, Antarctica – an Engineering
Perspective, in: OCEANS 2019 – Marseille, 1–8, IEEE,
https://doi.org/10.1109/OCEANSE.2019.8867206, 2019. a
Mostafapour, K., Nouri, N. M., and Zeinali, M.: The Effects of the Reynolds
Number on the Hydrodynamics Characteristics of an AUV, J.
Appl. Fluid Mech., 11, 343–352, https://doi.org/10.29252/jafm.11.02.28302, 2018. a
Nasmyth, P. W.: Oceanic turbulence, PhD thesis, University of British
Columbia, https://doi.org/10.14288/1.0302459, 1970. a, b
Nilsen, F., Fer, I., Baumann, T. M., Breivik, Ø., Czyz, C., Frank, L.,
Kalhagen, K., Koenig, Z., Kolås, E. H., Kral, S. T., Mabrouk, B. M. A.,
Mo-Bjørkelund, T., Muller, M., and Rabault, J.: Nansen Legacy Cruise
PC-2: Winter Process Cruise, Nansen Legacy Report Series, University of Tromsø – The Arctic University of Norway, https://doi.org/10.7557/nlrs.6324,
2021. a
Osborn, T. R. and Crawford, W. R.: An airfoil probe for measuring turbulent
velocity fluctuations in water, in: Air–Sea Interaction: Instruments
and Methods, edited by: Dobson, F., Hasse, L., and Davis, R., 369–386,
Plenum Press, New York, ISBN 978-14-6159-182-5, 1980. a
OSI SAF: Global Sea Ice Concentration (netCDF) – DMSP, EUMETSAT [data set],
https://doi.org/10.15770/EUM_SAF_OSI_NRT_2004, 2017. a
Palmer, M., Stephenson, G., Inall, M., Balfour, C., Düsterhus, A., and Green,
J.: Turbulence and mixing by internal waves in the Celtic Sea determined
from ocean glider microstructure measurements, J. Marine Syst.,
144, 57–69, https://doi.org/10.1016/j.jmarsys.2014.11.005, 2015. a, b
Panchev, S. and Kesich, D.: Energy spectrum of isotropic turbulence at large
wavenumbers, CR Acad. Bulg. Sci., 22, 627–630, 1969. a
Scheifele, B., Waterman, S., Merckelbach, L., and Carpenter, J. R.: Measuring
the Dissipation Rate of Turbulent Kinetic Energy in Strongly
Stratified, Low‐Energy Environments: A Case Study From the
Arctic Ocean, J. Geophys. Res.-Oceans, 123, 5459–5480,
https://doi.org/10.1029/2017JC013731, 2018. a
Schultze, L. K. P., Merckelbach, L. M., and Carpenter, J. R.: Turbulence and
Mixing in a Shallow Shelf Sea From Underwater Gliders, J. Geophys. Res.-Oceans, 122, 9092–9109, https://doi.org/10.1002/2017JC012872,
2017. a
Sousa, A., Madureira, L., Coelho, J., Pinto, J., Pereira, J., Borges Sousa, J.,
and Dias, P.: LAUV: The Man-Portable Autonomous Underwater
Vehicle, IFAC Proceedings Volumes, 45, 268–274,
https://doi.org/10.3182/20120410-3-PT-4028.00045, 2012.
a
Spingys, C. P., Garabato, A. C. N., Legg, S., Polzin, K. L., Abrahamsen, E. P.,
Buckingham, C. E., Forryan, A., and Frajka-Williams, E. E.: Mixing and
Transformation in a Deep Western Boundary Current: A Case
Study, J. Phys. Oceanogr., 51, 1205–1222,
https://doi.org/10.1175/JPO-D-20-0132.1, 2021. a
Thorpe, S. A., Osborn, T. R., Jackson, J. F. E., Hall, A. J., and Lueck, R. G.:
Measurements of Turbulence in the Upper-Ocean Mixing Layer Using
Autosub, J. Phys. Oceanogr., 33, 122–145,
https://doi.org/10.1175/1520-0485(2003)033<0122:MOTITU>2.0.CO;2, 2003. a
Yamazaki, H. and Osborn, T.: Dissipation estimates for stratified turbulence,
J. Geophys. Res.-Oceans, 95, 9739–9744,
https://doi.org/10.1029/JC095iC06p09739, 1990. a
Yamazaki, H., Lueck, R. G., and Osborn, T.: A Comparison of Turbulence
Data from a Submarine and a Vertical Profiler, J. Phys.
Oceanogr., 20, 1778–1786,
https://doi.org/10.1175/1520-0485(1990)020<1778:ACOTDF>2.0.CO;2, 1990. a, b
Short summary
A turbulence instrument was installed on a light autonomous underwater vehicle (AUV) and deployed in the Barents Sea in February 2021. We present the data quality and discuss limitations when measuring turbulence from the AUV. AUV vibrations contaminate the turbulence measurements, yet the measurements were sufficiently cleaned when the AUV operated in turbulent environments. In quiescent environments the noise from the AUV became relatively large, making the turbulence measurements unreliable.
A turbulence instrument was installed on a light autonomous underwater vehicle (AUV) and...