Evolution of an Intrathermocline Lens over the Lofoten Basin

  • Boris N. Filyushkin
  • Mikhail A. Sokolovskiy
  • Konstantin V. Lebedev
Chapter
Part of the Springer Oceanography book series (SPRINGEROCEAN)

Abstract

The Lofoten Basin of the Norwegian Sea is the main reservoir of heat in the Polar seas; it stands out as an area of high mesoscale activity and the existence of a quasi-permanent anticyclonic vortex. The observations of Argo floats over the period of 2005–2014 (17,600 profiles measured by 125 recorders) were used in the area of 55–80° N and 30–15° W, covering the Lofoten Basin. The Argo-based Model for Investigation of the Global Ocean (AMIGO) was used. The method makes it possible to obtain annual mean velocity fields and thermohaline characteristics up to a depth of 1500 m in 1° squares. One large-scale anticyclonic vortex covering the deepest part of the Lofoten area was observed in the depth column from 30 to 1500 m with velocity values increasing from 0–2 cm/s in the vortex center to 7–12 cm/s at its periphery. A local anticyclonic vortex (a lens of warm and saline waters) with a radius of about 35 km at depths of 250–700 m with an average long-term position of the center at 69.5° N and 3.5° E is also distinguished along the vertical distributions of thermohaline characteristics. In this contribution, we simulate the evolution of this lens, represented as an anticyclonic vortex patch located in the middle layer, within the framework of a three-layer quasi-geostrophic model using the Contour Dynamics Method. Calculations showed that the model can adequately reproduce the nature of the lens drift under the influences of various types of ocean currents and bottom topography. Comparison of the model results with the in situ observations of the vortex trajectories gives satisfactory results.

Notes

Acknowledgements

The work was supported by Russian Science Foundation (grant 14-50-00095) (analysis of the ocean data) and Ministry of Education and Science of the Russian Federation (grant 14.W03.31.0006, (numerical simulation), and Russian Foundation of Basic Research (grant 16-55-150001) (vortex dynamics).

References

  1. 1.
    Alekseev, G. V., Bagryantsev, M. V., Bogorodskiy, P. V., Vasin, V. V., & Shirokov, P. E. (1991). Structure and circulation of water in the area of anticyclonic eddy in the northeastern Norwegian Sea. Problems of the Arctic and Antarctic, 65, 14–23 (in Russian).Google Scholar
  2. 2.
    Alekseev, G. V., Nikolaev, Yu V, Romanov, A. A., Romantsev, V. A., & Sarukhanyan, E. I. (1986). Results of natural investigations in the Norwegian energy active zone. Itogi Nauki i Tekhniki, Atmosphere, Ocean, Space Program RAZREZY, 7, 46–72 (in Russian).Google Scholar
  3. 3.
    Argo. (2000). Argo float data and metadata from Global Data Assembly Center (Argo GDAC). SEANOE. http://doi.org/10.17882/42182.
  4. 4.
    Bashmachnikov, I. L., Sokolovskiy, M. A., Belonenko, T. V., Volkov, D. L., Isachsen, P. E., & Carton, X. (2017). On the vertical structure and stability of the Lofoten vortex in the Norwegian Sea. Deep-Sea Research Part I (in press).Google Scholar
  5. 5.
    Gascard, J.-C., & Mork, K. A. (2008). Climatic importance of large-scale and mesoscale circulation in the Lofoten Basin deduced from Lagrangian observations. In R. R. Dickson, J. Meincke, & P. Rhines (Eds.), Chapter 6: Arctic-Subarctic Ocean fluxes. Defining the role of the Northern Seas in climate (pp. 131–143). Dordrecht: Springer.Google Scholar
  6. 6.
    Ivanov, V. V., & Korablev, A. A. (1995). Formation and regeneration of the pycnocline lens in the Norwegian Sea. Russian Meteorology and Hydrology, 9, 62–69.Google Scholar
  7. 7.
    Ivanov, V. V., & Korablev, A. A. (1995). Interpycnocline lens dynamics in the Norwegian Sea. Russian Meteorology and Hydrology, 10, 32–37.Google Scholar
  8. 8.
    Köhl, A. (2007). Generation and stability of a quasi-permanent vortex in the Lofoten Basin. Journal of Physical Oceanography, 37, 2637–2651.CrossRefGoogle Scholar
  9. 9.
    Kozlov, V. F. (1984). Models of the topographic vortices in ocean (p. 200). Moscow: Nauka.Google Scholar
  10. 10.
    Lebedev, K. V. (2016). An argo-based model for investigation of the Global Ocean (AMIGO). Oceanology, 56, 172–181.CrossRefGoogle Scholar
  11. 11.
    Moshonkin, S. N., Bagno, A. V., Gusev, A. V., Filyushkin, B. N., & Zalesny, V. B. (2017). Physical properties of the Atlantic-Arctic water exchange formation. Izvestiya Atmospheric and Oceanic Physics, 53, 213–223.CrossRefGoogle Scholar
  12. 12.
    Orvik, K. A. (2004). The deepening of the Atlantic water in the Lofoten Basin of the Norwegian Sea, demonstrated by using an active reduced gravity model. Geophysical Research Letters, 31, L01306.  https://doi.org/10.1029/2003GL018687.CrossRefGoogle Scholar
  13. 13.
    Orvik, K. A., & Niiler, P. (2002). Major pathways of Atlantic water in the northern North Atlantic and Nordic Seas toward Arctic. Geophysical Research Letters, 29.  https://doi.org/10.1029/2002GL015002.
  14. 14.
    Poulain, P.-M., Warn-Varnas, A., & Niiler, P. P. (1996). Near-surface circulation of the Nordic Seas as measured by Lagrangian drifters. Journal Geophysical Research, 101, 18237–18258.CrossRefGoogle Scholar
  15. 15.
    Raj, R. P., Chafik, L., Nilsen, J. E. Ø., Eldevik, T., & Halo, I. (2015). The Lofoten Vortex of the Nordic Seas. Deep-Sea Research Part I, 96, 1–14.CrossRefGoogle Scholar
  16. 16.
    Raj, R. P., & Halo, I. (2016). Monitoring the mesoscale eddies of the Lofoten Basin: Importance, progress, and challenges. International Journal of Remote Sensing, 37, 3712–3728.CrossRefGoogle Scholar
  17. 17.
    Rodionov, V. B., & Kostianoy, A. G. (1998). Oceanic fronts of the North-European basin seas (293 pp.). Moscow: GEOS (in Russian). Google Scholar
  18. 18.
    Rossby, T., Ozhigin, V., Ivshin, V., & Bacon, Sh. (2009). An isopycnal view of the Nordic Seas hydrography with focus on properties of the Lofoten Basin. Deep-Sea Research Part I, 56, 1955–1971.CrossRefGoogle Scholar
  19. 19.
    Søiland, H., & Rossby, T. (2013). On the structure of the Lofoten Basin Eddy. Journal of Geophysical Research: Oceans, 118, 4201–4212.Google Scholar
  20. 20.
    Sokolovskiy, M. A. (1991). Modeling triple-layer vortical motions in the ocean by the Contour Dynamics Method. Izvestiya Atmospheric and Oceanic Physics, 27, 380–388.Google Scholar
  21. 21.
    Sokolovskiy, M. A., & Verron, J. (2014). Dynamics of vortex structures in a stratified rotating fluid. In Series Atmospheric and oceanographic sciences library (Vol. 47, p. 382). Switzerland: Springer International Publishing.Google Scholar
  22. 22.
    Voet, G., Quadfasel, D., Mork, K. A., & Søiland, H. (2010). The mid-depth circulation of the Nordic Seas derived from profiling float observations. Tellus, 62A, 516–529.CrossRefGoogle Scholar
  23. 23.
    Volkov, D. L., Belonenko, T. V., & Foux, V. R. (2013). Puzzling over the dynamics of the Lofoten Basin—A sub-Arctic hot spot of ocean variavility. Geophysical Reseach Letters, 40, 738–743.CrossRefGoogle Scholar
  24. 24.
    Volkov, D. L., Kubryakov, A. A., & Lumpkin, R. (2015). Formation and variability of the Lofoten Basin vortex in a high-resolution ocean model. Deep-Sea Research Part I, 105, 142–157.CrossRefGoogle Scholar
  25. 25.
    Zyryanov, V. N. (1995). Topographic eddies in sea currents dynamics (p. 240). Moscow: Water Problems Institute of RAS (in Russian).Google Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  • Boris N. Filyushkin
    • 1
  • Mikhail A. Sokolovskiy
    • 1
    • 2
  • Konstantin V. Lebedev
    • 1
  1. 1.Shirshov Institute of Oceanology, Russian Academy of SciencesMoscowRussia
  2. 2.Water Problems Institute, Russian Academy of SciencesMoscowRussia

Personalised recommendations