Articles | Volume 11, issue 3
https://doi.org/10.5194/os-11-343-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/os-11-343-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
12 May 2015
Research article |
| 12 May 2015
Deep drivers of mesoscale circulation in the central Rockall Trough
T. J. Sherwin
CORRESPONDING AUTHOR
Scottish Association for Marine Science, Scottish Marine Institute, Oban PA37 1QA, UK
D. Aleynik
Scottish Association for Marine Science, Scottish Marine Institute, Oban PA37 1QA, UK
E. Dumont
Scottish Association for Marine Science, Scottish Marine Institute, Oban PA37 1QA, UK
M. E. Inall
Scottish Association for Marine Science, Scottish Marine Institute, Oban PA37 1QA, UK
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Cited articles
Bacon, S.: Decadal variability in the outflow from the Nordic seas to the deep Atlantic Ocean, Nature, 394, 871–874, 1998.
Booth, D. A.: Eddies in the Rockall Trough, Oceanol. Acta, 11, 213–219, 1988.
Booth, D. A. and Ellett, D. J.: The Scottish continental-slope current, Cont. Shelf. Res., 2, 127–146, 1983.
Burrows, M., Thorpe, S. A., and Meldrum, D. T.: Dispersion over the Hebridean and Shetland shelves and slopes, Cont. Shelf. Res., 19, 49–55, 1999.
Dickson, R. R., Gould, W. J., Griffiths, C., Medler, K. J., and Gmitrowicz, E. M.: Seasonality in currents of the Rockall Channel, P. Roy. Soc. Edinb. B, 88, 103–125, 1986.
Ellett, D. J. and Martin, J. H. A.: The physical and chemical oceanography of the Rockall Channel, Deep-Sea Res., 20, 585–625, 1973.
Ellett, D. J. and Roberts, D.: The overflow of Norwegian Sea deep water across the Wyville-Thomson Ridge, Deep-Sea Res., 20, 819–835, 1973.
Ellett, D. J., Edwards, A., and Bowers, R.: The hydrography of the Rockall Channel – an overview, P. Roy. Soc. Edinb. B, 88, 61–81, 1986.
Ellett, D. J., Kruseman, P., Prangsma, G. J., Pollard, R. T., Van Aken, H. M., Edwards, A., Dooley, H. D., and Gould, W. J.: Water masses and mesoscale circulation of North Rockall Trough waters during JASIN 1978, Phil. Trans. R. Soc. Lond. A, 308, 213–252, 1983.
Eriksen, C. C., Osse, T. J., Light, R. D., Wen, T., Lehman, T. W., Sabin, P. L., Ballard, J. W., and Chiodi, A. M.: Seaglider: a long-range autonomous underwater vehicle for oceanographic research, IEEE J. Oceanic Eng., 26, 424–436, 2001.
Fratantoni, D. M.: North Atlantic surface circulation during the 1990's observed with satellite-tracked drifters, J. Geophys. Res., 106, 22067–22093, 2001.
Hakkinen, S. and Rhines, P.: Shifting surface currents in the northern North Atlantic Ocean, J. Geophys. Res., 114, C04005, https://doi.org/10.1029/2008JC004883, 2009.
Hansen, B. and Østerhus, S.: North Atlantic-Nordic Seas exchanges, Progr. Oceanogr., 45, 109–208, 2000.
Hansen, B., Hátún, H., Kristiansen, R., Olsen, S. M., and Østerhus, S.: Stability and forcing of the Iceland-Faroe inflow of water, heat, and salt to the Arctic, Ocean Sci., 6, 1013–1026, https://doi.org/10.5194/os-6-1013-2010, 2010.
Harvey, J.: Theta-S relationships and water masses in the eastern North Atlantic, Deep-Sea Res., 29, 1021–1033, 1982.
Hátún, H., Sando, A. B., Drange, H., Hansen, B., and Valdimarsson, H.: Influence of the Atlantic subploar gyre on the thermohaline circulation, Science, 309, 1841–1844, 2005.
Hátún, H., Eriksen, C. C., and Rhines, P. B.: Buoyant Eddies Entering the Labrador Sea Observed with Gliders and Altimetry, J. Phys. Oceanogr., 37, 2838–2854, 2007.
Heywood, K. J., McDonagh, E. L., and White, M. A.: Eddy kinetic energy of the North Atlantic Subpolar Gyre from satellite altimetry, J. Geophys. Res., 99, 22525–22539, 1994.
Holliday, N. P., Pollard, R. T., Read, J. F., and Leach, H.: Water mass properties and fluxes in the Rockall Trough, 1975–1998, Deep-Sea Res. Pt. I, 47, 1303–1332, 2000.
Holliday, N. P., Gary, S., Cunningham, C., Johnson, C., Griffiths, C., Read, J. F., and Sherwin, T.: Mulit-decadal varability of potential temperature, salinity and transport in the eastern Sub-polar Gyre North Atlantic, J. Geophys. Res., in review, 2015.
Hurrell, J. W.: Decadal trends in the North Atlantic Oscillation: regional temperatures and precipitation, Science, 269, 676–679, 1995.
Jakobsen, P. K., Ribergaard, M. H., Quadfasel, D., Schmith, T., and Hughes, C. W.: Near-surface circulation in the northern North Atlantic as inferred from Lagrangian drifters: variability from the mesoscale to interannual, J. Geophys. Res., 108, 3251, https://doi.org/10.1029/2002JC001554, 2003.
Johnson, C., Sherwin, T., Smythe-Wright, D., Shimmield, T., and Turrell, W.: Wyville Thomson Ridge overflow water: spatial and temporal distribution in the Rockall Trough, Deep-Sea Res. Pt. I, 57, 1153–1162, 2010.
Johnson, C., Inall, M., and Hakkinen, S.: Declining nutrient concentrations in the northeast Atlantic as a result of a weakening Subpolar Gyre, Deep-Sea Res. Pt. I, 82, 95–107, 2013.
Lankhorst, M. and Zenk, W.: Lagrangian observations of the middepth and deep velocity fields of the northeastern Atlantic Ocean, J. Phys. Oceanogr., 36, 43–63, 2006.
Martin, J. P., Lee, C. M., Eriksen, C. C., Ladd, C., and Kachel, N. B.: Glider observations of kinematics in a Gulf of Alaska eddy, J. Geophys. Res.-Oceans, 114, C12021, https://doi.org/10.1029/2008JC005231, 2009.
McCartney, M. S. and Mauritzen, C.: On the origin of the warm inflow to the Nordic Seas, Prog. Oceanogr., 51, 125–214, 2001.
Merckelbach, L. M., Briggs, R. D., Smeed, D. A., and Griffiths, G.: Current measurements from autonomous underwater gliders, in: EEE/OES 9th Working Conference on Current Measurement Technology, Charleston, 17–19 March 2008, 61–67, 2008.
Perry, M. J., Sackmann, B. S., Eriksen, C. C., and Lee, C. M.: Seaglider observations of blooms and subsurface chlorophyll maxima off the Washington coast, Limnol. Oceanogr., 53, 2169–2179, 2008.
Pickart, R. S., Spall, M. A., Ribergaard, M. H., Moore, G. W. K., and Milliff, R. F.: Deep convection in the Irminger Sea forced by the Greenland tip jet, Nature, 424, 152–156, 2003.
Pollard, R. T., Guymer, T. H., and Taylor, P. K.: Summary of the JASIN 1978 field experiement, Philisophical Transactions of the Royal Society of London A, 308, 221–230, 1983.
Reid, J. L.: On the contribution of the Mediterranean Sea outflow to the Norwegian-Greenland Sea, Deep-Sea Res., 26, 1199–1223, 1979.
Rio, M. H., Guinehut, S., and Larnicol, G.: New CNES-CLS09 global mean dynamic topography computed from the combination of GRACE data, altimetry, and in situ measurements, J. Geophys. Res.-Oceans, 116, C07018, https://doi.org/10.1029/2010JC006505, 2011.
Sherwin, T. J., Griffiths, C. R., Inall, M. E., and Turrell, W. R.: Quantifying the overflow across the Wyville Thomson Ridge into the Rockall Trough, Deep-Sea Res. Pt. I, 55, 396–404, 2008.
Sherwin, T. J., Aldridge, D., Allen, J., Amin, S., Attard, K., Beaton, J., Brand, T., Barnard, C., Calderwood, J., Dumont, E., Hebden, M., Ivanov, V., Macey, A., Marsay, C., McLachlan, R., McRae, J., Mogg, A., Mohammed, K., Porter, M., Read, J., Rerolle, V., Richier, S., Short, J., Steigenberger, S., and Wager, N.: Cruise D340a: Reykjavik to Dunstaffnage via Rockall and the Wyville Thomson Ridge, Scottish Association of Marine Science, Oban, UK, 196 pp., 2009.
Sherwin, T. J., Read, J. F., Holliday, N. P., and Johnson, C.: The impact of changes in North Atlantic Gyre distribution on water mass characteristics in the Rockall Trough, ICES J. Mar. Sci., 69, 751–757, 2012.
Souza, A. J., Simpson, J. H., Harikrishnan, M., and Malarkey, J.: Flow structure and seasonality in the Hebridean slope current, Oceanol. Acta, 24, S63–S76, 2001.
Tett, S. B. F., Sherwin, T. J., Shravat, A., and Browne, O.: How much has the North Atlantic Ocean overturning circulation changed in the last 50 years?, J. Climate, 27, 6325–6342, 2014.
Thurnherr, A.: A practical assessment of the errors associated with full-depth LADCP profiles obtained using Teledyne RDI Workhorse acoustic Doppler current profilers, J. Atmos. Ocean. Tech., 27, 1215–1227, 2010.
Ullgren, J. and White, M.: Water mass interaction at intermediate depths in the southern Rockall Trough, northeastern North Atlantic, Deep-Sea Res. Pt. I, 57, 248–257, 2010.
Ullgren, J. and White, M.: Observations of mesoscale variability in the Rockall Trough, Deep-Sea Res. Pt. I, 64, 1–8, 2012.
Volkov, D. L.: Interannual variability of the altimetry-derived eddy field and surface circulation in the extratropical North Atlantic Ocean in 1993–2001, J. Phys. Oceanogr., 35, 405–426, 2005.
Short summary
The Rockall Trough feeds warm salty water to Polar regions and the European Shelf. Detailed observations from an underwater glider show that a) the meandering surface current field in the central trough is driven by deep eddies; b) chance circulations deflect the eastern slope current and warm the western side; c) and altimeter observations omit the mean flow in the narrow slope current. There are wider implications for satellite altimeter observations, ocean monitoring and ocean model results.
The Rockall Trough feeds warm salty water to Polar regions and the European Shelf. Detailed...
