Here I review the use of two highly complementary acoustical technologies for measuring currents in the ocean: acoustically tracked neutrally buoyant floats and vessel-mounted acoustic Doppler current profilers (ADCPs). The beauty of floats lies in their ability to efficiently and accurately visualize fluid motion in fronts and vortices and the dispersion caused by mesoscale eddy processes. Floats complement classical hydrography by articulating mechanisms and pathways by which waters spread out from their source region. Vessel-mounted ADCPs can profile the water column at (1 km) horizontal resolution to depths greater than 1,000 m. These vessel-based scans capture in detail the cross-stream structure of fronts and eddies as well as the impact of bathymetry on currents. Sustained sampling along selected routes builds up valuable databases both for statistical studies of the submesoscale velocity field and for accurate estimates of fluid transport, as well as how these vary over time.


Article metrics loading...

Loading full text...

Full text loading...


Literature Cited

  1. Armi L, Hebert D, Oakey N, Price J, Richardson P. et al. 1989. Two years in the life of a Mediterranean salt lens. J. Phys. Oceanogr. 19:354–70 [Google Scholar]
  2. Armi L, Zenk W. 1984. Large lenses of highly saline Mediterranean Water. J. Phys. Oceanogr. 14:1560–76 [Google Scholar]
  3. Boebel O, Rossby T, Lutjeharms J, Zenk W, Barron C. 2003. Path and variability of the Agulhas Return Current. Deep-Sea Res. II 50:35–56 [Google Scholar]
  4. Boebel O, Schultz Tokos KL, Zenk W. 1995. Calculation of salinity from neutrally buoyant RAFOS floats. J. Atmos. Ocean. Technol. 12:923–34 [Google Scholar]
  5. Bower AS. 1989. Potential vorticity balances and horizontal divergence along particle trajectories in Gulf Stream meanders east of Cape Hatteras. J. Phys. Oceanogr. 19:1669–81 [Google Scholar]
  6. Bower AS. 1991. A simple kinematic mechanism for mixing fluid parcels across a meandering jet. J. Phys. Oceanogr. 21:173–80 [Google Scholar]
  7. Bower AS, Armi L, Ambar I. 1995. Direct evidence of meddy formation off the southwestern coast of Portugal. Deep-Sea Res. I 42:1621–30 [Google Scholar]
  8. Bower AS, Armi L, Ambar I. 1997. Lagrangian observations of meddy formation during a Mediterranean undercurrent seeding experiment. J. Phys. Oceanogr. 27:2545–75 [Google Scholar]
  9. Bower AS, Furey HH. 2012. Mesoscale eddies in the Gulf of Aden and their impact on the spreading of Red Sea Outflow Water. Prog. Oceanogr. 96:14–39 [Google Scholar]
  10. Bower AS, Le Cann B, Rossby T, Zenk W, Gould J. et al. 2002. Directly measured mid-depth circulation in the northeastern North Atlantic Ocean. Nature 419:603–7 [Google Scholar]
  11. Bower AS, Lozier S, Gary S. 2011. Export of Labrador Sea Water from the subpolar North Atlantic: a Lagrangian perspective. Deep-Sea Res. II 58:1798–818 [Google Scholar]
  12. Bower AS, Rossby T. 1989. Evidence of cross-frontal exchange processes in the Gulf Stream based on isopycnal RAFOS float data. J. Phys. Oceanogr. 19:1177–90 [Google Scholar]
  13. Bracco AL, Pedlosky J, Pickart RS. 2008. Eddy formation near the west coast of Greenland. J. Phys. Oceanogr. 38:1992–2002 [Google Scholar]
  14. Brooks D, Bane JM Jr. 1983. Gulf Stream meanders off North Carolina during winter and summer 1979. J. Geophys. Res. 88:4633–50 [Google Scholar]
  15. Chafik L, Rossby T, Schrum C. 2014. On the spatial structure and temporal variability of poleward transport between Scotland and Greenland. J. Geophys. Res. 119:824–41 [Google Scholar]
  16. Chelton DB, Schlax MG. 1996. Global observations of oceanic Rossby waves. Science 272:234–38 [Google Scholar]
  17. Chelton DB, Schlax MG, Samelson RM. 2011. Global observations of nonlinear mesoscale eddies. Prog. Oceanogr. 91:167–216 [Google Scholar]
  18. Childers KH, Flagg CN, Rossby T. 2014. Direct velocity observations of volume flux between Iceland and the Shetland Islands. J. Geophys. Res. 119:5934–44 [Google Scholar]
  19. Childers KH, Flagg CN, Rossby T, Schrum C. 2015. Directly measured currents and estimated transport pathways of Atlantic Water between 59.5°N and the Iceland-Faroes-Scotland Ridge. Tellus A 67:28067 [Google Scholar]
  20. Collins CA, Margolina T, Rago TA, Ivanov L. 2013. Looping RAFOS floats in the California Current System. Deep-Sea Res. II 85:42–61 [Google Scholar]
  21. Cushman-Roisin B. 1987. Subduction. Dynamics of the Ocean Surface Mixed Layer: Proceedings of the ‘Aha Huliko'a Hawaiian Winter Workshop P Müller, D Henderson 181–96 Honololu: Hawaii Inst. Geophys. [Google Scholar]
  22. Dutkiewicz S, Rothstein L, Rossby T. 2001. Pathways of cross-frontal exchange in the North Atlantic Current. J. Geophys. Res. 106:26917–28 [Google Scholar]
  23. Fischer G, Lee D, O'Bara M, Kasturi P, Rossby T, Recksiek C. 2007. Tracking small fish with a microwatt acoustic receiver—an archival tag development. IEEE J. Ocean. Eng. 31:975–85 [Google Scholar]
  24. Flagg CN, Schwartze G, Gottlieb E, Rossby T. 1998. Operating an acoustic Doppler current profiler aboard a container vessel. J. Atmos. Ocean. Technol. 15:257–71 [Google Scholar]
  25. Flierl G. 1981. Particle motions in large-amplitude wave fields. Geophys. Astrophys. Fluid Dyn. 18:39–74 [Google Scholar]
  26. Freeland HJ, Rhines P, Rossby T. 1975. Statistical observations of the trajectories of neutrally buoyant floats in the North Atlantic. J. Mar. Res. 33:383–404 [Google Scholar]
  27. Fu L-L, Keffer T, Niiler PP, Wunsch C. 1982. Observations of mesoscale variability in the western North Atlantic: a comparative study. J. Mar. Res. 40:809–48 [Google Scholar]
  28. Halkin D, Rossby T. 1985. The structure and transport of the Gulf Stream at 73°W. J. Phys. Oceanogr. 15:1439–52 [Google Scholar]
  29. Hansen B, Østerhus S. 2000. North Atlantic–Nordic Seas exchanges. Prog. Oceanogr. 45:109–208 [Google Scholar]
  30. Hebert D, Oakey N, Ruddick B. 1990. Evolution of a Mediterranean salt lens: scalar properties. J. Phys. Oceanogr. 20:1468–83 [Google Scholar]
  31. Hebert D, Rossby T. 2006. The Lagrangian isopycnal dispersion experiment Poster Pap. OS25O-20, presented at Am. Geophys. Union Ocean Sci. Meet., Honolulu, Feb. 20–24 [Google Scholar]
  32. Hogg NG, Stommel HM. 1990. How currents in the upper thermocline could advect meddies deeper down. Deep-Sea Res. I 37:613–23 [Google Scholar]
  33. Hormazabal S, Combes V, Morales CE, Correa-Ramirez MA, Di Lorenzo E, Nuñez S. 2013. Intrathermocline eddies in the coastal transition zone off central Chile (31–41°S). J. Geophys. Res. 118:4811–21 [Google Scholar]
  34. Isachsen PE. 2015. Baroclinic instability and the mesoscale eddy field around the Lofoten Basin. J. Geophys. Res. 120:2884–903 [Google Scholar]
  35. Iselin CO. 1936. A study of the circulation of the western North Atlantic. Pap. Phys. Oceanogr. Meteorol. 4:1–101 [Google Scholar]
  36. Johns WE. 1988. One-dimensional baroclinically unstable waves on the Gulf Stream potential vorticity gradient near Cape Hatteras. Dyn. Atmos. Oceans 11:323–50 [Google Scholar]
  37. Johns WE, Shay TJ, Bane JM, Watts DR. 1995. Gulf Stream structure, transport and recirculation near 68°W. J. Geophys. Res. 100:817–38 [Google Scholar]
  38. Johnson GC, McTaggart KE. 2010. Equatorial Pacific 13°C water eddies in the eastern subtropical South Pacific Ocean. J. Phys. Oceanogr. 40:226–36 [Google Scholar]
  39. Kassis P. 2000. Submesoscale coherent vortices in the deep Brazil Basin MS Thesis, Mass. Inst. Technol., Cambridge, MA, and Woods Hole Oceanogr. Inst., Woods Hole, MA [Google Scholar]
  40. Kearns EJ, Rossby T. 1998. Historical position of the North Atlantic Current. J. Geophys. Res. 103:15509–24 [Google Scholar]
  41. Köhl A. 2007. Generation and stability of a quasi-permanent vortex in the Lofoten Basin. J. Phys. Oceanogr. 37:2637–51 [Google Scholar]
  42. LaCasce JH. 2008. Statistics from Lagrangian observations. Prog. Oceanogr. 77:1–29 [Google Scholar]
  43. LaCasce JH, Bower AS. 2000. Relative dispersion in the subsurface North Atlantic. J. Mar. Res. 58:863–94 [Google Scholar]
  44. Lazarevich P, Rossby T, McNeil C. 2004. Oxygen variability in the near-surface waters of the northern North Atlantic: observations and a model. J. Mar. Res. 62:663–83 [Google Scholar]
  45. Le Cann B, Assenbaum M, Gascard J-C, Reverdin G. 2005. Observed mean and mesoscale upper ocean circulation in the midlatitude northeast Atlantic. J. Geophys. Res. 110:C07S05 [Google Scholar]
  46. Lilly JM, Rhines PB, Schott F, Lavender K, Lazier J. et al. 2003. Observations of the Labrador Sea eddy field. Prog. Oceanogr. 59:75–176 [Google Scholar]
  47. Luce D, Rossby T. 2008. On the size and distribution of rings and coherent vortices in the Sargasso Sea. J. Geophys. Res. 113:C05011 [Google Scholar]
  48. Mauritzen C, Price J, Sanford T, Torres D. 2005. Circulation and mixing in the Faroese Channels. Deep-Sea Res. I 52:883–913 [Google Scholar]
  49. Maximenko N, Yamagata T. 1995. Submesoscale anomalies in the North Pacific Subarctic Front. J. Geophys. Res. 100:18459–69 [Google Scholar]
  50. McDowell SE, Rossby T. 1978. A mesoscale lens of Mediterranean water off the Bahamas. Science 202:1085–87 [Google Scholar]
  51. McWilliams JC, Taft BA. 1986. Introduction to a collection of papers on the POLYMODE local dynamics experiment. J. Phys. Oceanogr. 16:401 [Google Scholar]
  52. Müller TJ, Siedler G. 1992. Multi-year current time series in the eastern North Atlantic Ocean. J. Mar. Res. 50:63–98 [Google Scholar]
  53. Newton CW. 1978. Fronts and wave disturbances in Gulf Stream and atmospheric jet stream. J. Geophys. Res. 83:4697–706 [Google Scholar]
  54. Ollitrault M, Colin de Verdiere A. 2002. SOFAR floats reveal midlatitude intermediate North Atlantic general circulation. Part I: a Lagrangian descriptive view. J. Phys. Oceanogr. 32:2020–33 [Google Scholar]
  55. Pérez-Brunius P, Rossby T, Watts DR. 2004a. Absolute transports of mass and temperature for the North Atlantic Current–subpolar front system. J. Phys. Oceanogr. 34:1870–83 [Google Scholar]
  56. Pérez-Brunius P, Rossby T, Watts DR. 2004b. A method to obtain the mean transports of ocean currents by combining isopycnal float data with historical hydrography. J. Atmos. Ocean. Technol. 21:298–316 [Google Scholar]
  57. Piip AT. 1969. Large cells of Mediterranean water in the Madeira Canaries region. Eos Trans. AGU 50:193 (Abstr.) [Google Scholar]
  58. Prater MD. 2002. Eddies in the Labrador Sea as observed by profiling RAFOS floats and remote sensing. J. Phys. Oceanogr. 32:411–27 [Google Scholar]
  59. Prater MD, Rossby T. 1999. An alternative hypothesis for the origin of the “Mediterranean” salt lens observed in the Bahamas in the fall of 1976. J. Phys. Oceanogr. 29:2103–9 [Google Scholar]
  60. Price JF, Rossby T. 1982. Observations of a barotropic planetary wave in the western North Atlantic. J. Mar. Res. 40:Suppl.543–58 [Google Scholar]
  61. Richardson P, Bower AS, Zenk W. 2000. A census of meddies tracked by floats. Prog. Oceanogr. 45:209–50 [Google Scholar]
  62. Rodrigues RR, Wimbush M, Watts DR, Rothstein LM, Ollitrault M. 2010. South Atlantic mass transports obtained from subsurface float and hydrographic data. J. Mar. Res. 68:819–50 [Google Scholar]
  63. Rossby T. 1987. On the energetics of the Gulf Stream at 73°W. J. Mar. Res. 45:59–82 [Google Scholar]
  64. Rossby T. 1996. The North Atlantic Current and surrounding waters: at the crossroads. Rev. Geophys. 34:463–81 [Google Scholar]
  65. Rossby T. 2007. Evolution of Lagrangian methods in oceanography. Lagrangian Analysis and Prediction of Coastal and Ocean Dynamics A Griffa, AD Kirwan Jr., AJ Mariano, T Özgökmen, T Rossby 1–38 Cambridge, UK: Cambridge Univ. Press [Google Scholar]
  66. Rossby T. 2014. On the structure and distribution of thin anti-cyclonic lenses in the southeast Pacific Ocean. J. Mar. Res. 72:383–403 [Google Scholar]
  67. Rossby T, Flagg CN. 2012. Direct measurement of volume flux in the Faroe-Shetland Channel and over the Iceland-Faroe Ridge. Geophys. Res. Lett. 39:L07602 [Google Scholar]
  68. Rossby T, Flagg CN, Donohue K. 2010. On the variability of Gulf Stream transport from seasonal to decadal timescales. J. Mar. Res. 68:503–22 [Google Scholar]
  69. Rossby T, Flagg CN, Donohue K, Sanchez-Franks A, Lillibridge J. 2014. On the long-term stability of Gulf Stream transport based on 20 years of direct measurements. Geophys. Res. Lett. 41:114–20 [Google Scholar]
  70. Rossby T, Flagg CN, Ortner P, Hu C. 2011. A tale of two eddies: diagnosing coherent eddies through acoustic remote sensing. J. Geophys. Res. 116:C12017 [Google Scholar]
  71. Rossby T, Levine ER, Conners DN. 1985. The isopycnal Swallow float—a simple device for tracking water parcels in the ocean. Prog. Oceanogr. 14:511–25 [Google Scholar]
  72. Rossby T, Prater MD. 2005. On variations in static stability along Lagrangian trajectories. Deep-Sea Res. II 52:465–79 [Google Scholar]
  73. Rossby T, Prater MD, Søiland H. 2009. Pathways of inflow and dispersion of warm waters in the Nordic Seas. J. Geophys Res. 114:C04011 [Google Scholar]
  74. Rossby T, Riser S, Mariano A. 1983. The western North Atlantic: a Lagrangian viewpoint. Eddies in Marine Science AR Robinson 66–91 Berlin: Springer-Verlag [Google Scholar]
  75. Rossby T, Zhang HM. 2001. The near-surface velocity and potential vorticity structure of the Gulf Stream. J. Mar. Res. 59:949–75 [Google Scholar]
  76. Sato O, Rossby T. 1995. Seasonal and secular variations in dynamic height anomaly and transport of the Gulf Stream. Deep-Sea Res. I 42:149–64 [Google Scholar]
  77. SCOR (Sci. Comm. Ocean. Res.), IAPSO (Int. Assoc. Phys. Sci. Oceans) 2012. OceanScope: a proposed partnership between the maritime industries and the ocean observing community to monitor the global ocean water column Rep., SCOR/IAPSO Work. Group 133, Int. Counc. Sci., Paris [Google Scholar]
  78. Shoosmith DR, Richardson PL, Bower AS, Rossby T. 2005. Discrete eddies in the northern North Atlantic as observed by looping RAFOS floats. Deep-Sea Res. II 52:627–50 [Google Scholar]
  79. Søiland H, Prater MD, Rossby T. 2008. Rigid topographic control of currents in the Nordic Seas. Geophys. Res. Lett. 35:L18607 [Google Scholar]
  80. Song T, Rossby T. 1997. Analysis of Lagrangian potential vorticity balance and lateral displacement of water parcels in Gulf Stream meanders. J. Phys. Oceanogr. 27:325–39 [Google Scholar]
  81. Song T, Rossby T, Carter E Jr. 1995. Lagrangian studies of fluid exchange between the Gulf Stream and surrounding waters. J. Phys. Oceanogr. 25:46–63 [Google Scholar]
  82. Starr V. 1968. Physics of Negative Viscosity Phenomena New York: McGraw-Hill [Google Scholar]
  83. Van Uffelen LJ, Nosal E-M, Howe BM, Carter GS, Worcester PF. et al. 2013. Estimating uncertainty in subsurface glider position using transmissions from fixed acoustic tomography sources. J. Acoust. Soc. Am. 134:3260 [Google Scholar]
  84. Worst JS, Donohue KA, Rossby T. 2014. A comparison of vessel-mounted acoustic Doppler current profiler and satellite altimeter estimates of sea surface height and transports between New Jersey and Bermuda along the CMW Oleander route. J. Atmos. Ocean. Technol. 31:1422–33 [Google Scholar]
  85. Worthington LV. 1976. On the North Atlantic Circulation Johns Hopkins Oceanogr. Stud. 6. Baltimore, MD: Johns Hopkins Univ. Press [Google Scholar]

Data & Media loading...

  • Article Type: Review Article
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error