Circulation in the Mediterranean Sea (original) (raw)

Abstract

The overall functioning of the Mediterranean Sea, which transforms Atlantic Water (AW) into Mediterranean Waters (MWs), has been comprehended for a while, and the process of dense water formation, which leads AW to sink offshore in specific northern zones of the Western and the Eastern Basins, has been studied in the world ocean. However, the circulation of the various waters from/to the basins openings to/from the zones of sinking is still debated in the Western Basin, while a similar debate is only being initiated in the Eastern Basin. The differences between the circulation schemas published up to now can be large and they have already been commented upon in papers published recently. To provide a coherent introductory chapter, only the authors’ analysis is presented hereafter.

Overall, and due to the Coriolis effect, all waters (AW and MWs) that circulate at basin scale tend to follow, in the counterclockwise sense, the isobaths at their own level. Hence they tend to describe, in both the Western and the Eastern Basins, quasi permanent gyres a few 10s km thick and a few 1000s km long along the continental slope. This simple schema is complicated by the fact that the southern parts of both gyres described by AW are markedly unstable, the AW inflow being hence identified with the so-called Algerian Current and Libyo-Egyptian Current and generating specific systems over the whole depth. Indeed, these currents (100–200 m deep) meander and generate, a few times per year, anticyclonic eddies that can reach diameters of 100–200 km (and even more), propagate downstream (i.e. eastward) at speeds up to a few km/day, and sometimes extend down to the bottom (2–3000 m). Hence, these eddies follow the deeper isobaths, separate from their parent current where these isobaths diverge from the upper continental slope, and drift for years (up to 3 at least) in the central part of the basins, possibly coming back shoreward where they interact with their parent current, sometimes in a dramatic way. These eddies entrain AW and MWs from the peripheral part of the basins towards their central part, together with eddies induced by the wind in the Eastern Basin only and having similar characteristics. In both basins, the northern parts of the gyres display specific features linking them to the zones of AW sinking, hence being identified (more easily in the Western Basin than in the Eastern one due to the topography) with the so-called Northern Currents. In addition to these circulation features, and because the various openings are only a few 100s m deep, the deeper MWs must be uplifted before outflowing. This is achieved permanently and more or less everywhere through continuous mixing with less dense waters and uplifting by newly formed denser waters. This is also achieved when and where intense mixing with other waters (cascading from sills or sinking) and sucking upward straits occur.

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Abbreviations

ADCP:

acoustic Doppler current profiler

AW:

Atlantic water

AdDW:

Adriatic deep water

AeDW:

Aegean deep water

AVHRR:

advanced very high resolution radiometer

CTD:

conductivity (to compute salinity) temperature depth (actually pressure) probe

LIW:

Levantine intermediate water

MWs:

Mediterranean waters

NOAA:

national oceanic and atmospheric administration

POEM:

physical oceanography of the Eastern Mediterranean

SST:

sea surface temperature

TDW:

Tyrrhenian dense water

WMDW:

Western Mediterranean deep water

XBT:

EXpendable BathyThermograph probe

XCTD:

EXpendable Conductivity Temperature Depth probe

References

  1. Millot C (1992) Are there major differences between the largest Mediterranean seas? A preliminary investigation. Bulletin de l’Institut Océanographique, Monaco 11:3–25
    Google Scholar
  2. Le Vourch J, Millot C, Castagné N, Le Borgne P, Olry JP (1992) Atlas of Thermal Fronts of the Mediterranean Sea Derived From Satellite Imagery. Mémoires de l’Institut Océanographique, Monaco, 16, 146p
    Google Scholar
  3. Millot C, Taupier-Letage I (2005) Additional evidence of LIW entrainment across the Algerian Basin by mesoscale eddies and not by a permanent westward-flowing vein. Prog Oceanogr (in press)
    Google Scholar
  4. Robinson AR, Golnaraghi M (1993) Circulation and dynamics of the Eastern Mediterranean Sea; quasi-synoptic data-driven simulations. Deep Sea Res 40(6):1207
    Article Google Scholar
  5. Malanotte-Rizzoli P, Manca BB, Ribera d’Alcala M, Theocharis A, Bergamasco A, Bregant D, Budillon G, Civitarese G, Georgopoulos D, Michelato A, Sansone E, Scarazzato P, Souvermezoglou E (1997) A synthesis of the Ionian Sea hydrography, circulation and water mass pathways during POEM-Phase I. Prog Oceanogr 39:153
    Article Google Scholar
  6. Nielsen JN (1912) Hydrography of the Mediterranean and adjacent waters. Rep Dan Oceanogr Exp Medit 1:77
    Google Scholar
  7. Hamad N, Millot C, Taupier-Letage I (2005) A new hypothesis about the surface circulation in the eastern basin of the Mediterranean Sea. Prog Oceanogr (in press)
    Google Scholar
  8. Alhammoud B, Béranger K, Mortier L, Crépon M, Dekeyser I (2004) Surface circulation of the Levantine Basin: comparison of model results with observations. Prog Oceanogr (in press)
    Google Scholar
  9. Millot C (1999) Circulation in the Western Mediterranean sea. J Mar Sys 20(1–4):423–442
    Article Google Scholar
  10. Millot C (1985) Some features of the Algerian Current. J Geophys Res 90(C4):7169–7176
    Article CAS Google Scholar
  11. Puillat I, Taupier-Letage I, Millot C (2002) Algerian eddies lifetimes can near 3 years. J Mar Sys 31(4):245–259
    Article Google Scholar
  12. Fuda J-L, Millot C, Taupier-Letage I, Send U, Bocognano JM (2000) XBT monitoring of a meridian section across the Western Mediterranean Sea. Deep Sea Res I 47:2191–2218
    Article Google Scholar
  13. Ruiz S, Font J, Emelianov M, Isern-Fontanet J, Millot C, Taupier-Letage I (2002) Deep structure of an open sea eddy in the Algerian Basin. J Mar Sys 33–34:179–195
    Article Google Scholar
  14. Taupier-Letage I, Millot C (1988) Surface circulation in the Algerian Basin during 1984. Oceanol Acta 9:119–131
    Google Scholar
  15. Millot C (1991) Mesoscale and seasonal variabilities of the circulation in the Western Mediterranean. Dyn Atm Oceans 15:179–214
    Article Google Scholar
  16. Béranger K, Mortier L, Crépon M (2005) Seasonal variability of transports through the Gibraltar, Sicily and Corsica straits from a high resolution Mediterranean model. Prog Oceanogr (in press)
    Google Scholar
  17. Albérola C, Millot C, Font J (1995) On the seasonal and mesoscale variabilities of the Northern Current during the PRIMO-0 experiment in the Western Mediterranean Sea. Oceanol Acta 18(2):163–192
    Google Scholar
  18. Wald L (1985) Apport de la télédétection spatiale en infrarouge proche et moyen à la connaissance du milieu marin: relations entre le champ de températures et le champ de courant, observations de l’état de surface et mesures de la vitesse du vent, la dynamique de la couche superficielle en Mer Ligure. Thèse de Doctorat d’Etat, Université de Toulon et du Var, France
    Google Scholar
  19. Taupier-Letage I, Millot C (1986) General hydrodynamical features in the Ligurian Sea inferred from the DYOME experiment. Oceanol Acta 9(2):119–131
    Google Scholar
  20. Schott F, Leaman K (1991) Observations with moored acoustic Doppler current profilers in the convection regime in the Golfe du Lion. J Phys Oceanogr 21:558–574
    Article Google Scholar
  21. Millot C, Monaco A (1984) Deep intense currents and sedimentary transport in the Northwestern Mediterranean Sea. Geo-Marine Lett 4(1):13–17
    Article Google Scholar
  22. Millot C (1990) The Gulf of Lions’ hydrodynamics. Continental Shelf Res 10(9–11):885–894
    Article Google Scholar
  23. Millot C (1979) Wind induced upwellings in the Gulf of Lions. Oceanol Acta 2(3):261–274
    Google Scholar
  24. Lopez-Garcia MJ, Millot C, Font J, Garcia-Ladona E (1994) Surface circulation variability in the Balearic Basin. J Geophys Res 99(C2):3285–3296
    Article Google Scholar
  25. Fuda J-L, Etiope G, Millot C, Favali P, Calcara M, Smriglio G, Boschi E (2002) Warming, salting and origin of the Tyrrhenian Deep Water. Geophys Res Lett 29(18):1886, doi:10.1029/2001GL014072
    Article Google Scholar
  26. Lermusiaux PFJ, Robinson AR (1997) Features of dominant mesoscale variability, circulation patterns and dynamics in the Strait of Sicily. Deep Sea Res 48(9):1953–1997
    Article Google Scholar
  27. Salas J, Millot C, Font J, García-Ladona E (2002) Analysis of mesoscale phenomena in the Algerian Basin observed with drifting buoys and infrared images. Deep Sea Res 49(2):245–266
    Article Google Scholar
  28. Pierini S, Rubino A (2001) Modelling the oceanic circulation in the area of the strait of Sicily: the remotely forced dynamics. J Phys Oceanogr 31(6):1397–1412
    Article Google Scholar
  29. Ovchinnikov I, Popov Y, Gertman I (1990) Investigation of the formation of deep waters in the Eastern Mediterranean sea during the 36th cruise of the R/V Ya. Oceanology 30(6):769–771
    Google Scholar
  30. Millot C (1987) Circulation in the Western Mediterranean. Oceanol Acta 10(2):143–149
    Google Scholar
  31. Astraldi M, Gasparini G-P, Gervasio L, Salusti E (2001) Dense water dynamics along the Strait of Sicily (Mediterranean Sea). J Phys Oceanogr 31(12):3457–3475
    Article Google Scholar
  32. Klein B, Roether W, Manca B, Bregant D, Beitzel V, Kovacevic V, Lucchetta A (1999) The large deep water transient in the Eastern Mediterranean. Deep Sea Res 46:371–414
    Article Google Scholar
  33. Lacombe H, Tchernia P, Gamberoni L (1985) Variable bottom water in the Western Mediterranean basin. Prog Oceanogr 14:319–338
    Article Google Scholar
  34. Sparnocchia S, Gasparini GP, Astraldi M, Borghini M, Pistek P (1999) Dynamics and mixing of the Eastern Mediterranean outflow in the Tyrrhenian Basin. J Mar Syst 20:301–317
    Article Google Scholar
  35. Kinder T, Parrilla G (1987) Yes, some of the Mediterranean outflow does come from great depths. J Geophys Res 92:2901–2906
    Article Google Scholar
  36. Testor P, Gascard J-C (2004) Large scale flow separation and mesoscale eddy formation in the Algerian Basin. Prog Oceanogr (in press)
    Google Scholar
  37. Millot C, Taupier-Letage I, Benzohra M (1997) Circulation off Algeria inferred from the Médiprod-5 current meters. Deep Sea Res 44(9–10):1467–1495
    Article Google Scholar
  38. Crépon M, Boukthir M, Barnier B, Aikman III F (1989) Horizontal ocean circulation forced by deep water formation: Part I. An analytical study. J Phys Oceanogr 19:1781–1792
    Article Google Scholar
  39. Ozsoy E, Rank D, Salihoglu I (2002) Pycnocline and deep mixing in the Black Sea: stable isotope and transient tracer measurements. Estuarine, Coastal and Shelf Sci 54(3):621–629
    Article Google Scholar
  40. Ginzburg A, Kostianoy A, Nezlin N, Soloviev D, Stanichny S (2002) Anticyclonic eddies in the northwestern Black Sea. J Mar Sys 32:91–106
    Article Google Scholar
  41. Albérola C, Rousseau S, Millot C, Astraldi M, Garcia-Lafuente JJ, Gasparini GP, Send U, Vangriesheim A (1995) Tidal currents in the Western Mediterranean Sea. Oceanol Acta 18(2):273–284
    Google Scholar
  42. van Haren H, Millot C (2005) Rectilinear and circular inertial motions in the Western Mediterranean Sea. Deep-Sea Res I 51(11):1441–1455, doi:10.1016/j.dsr.2004.07.009
    Google Scholar
  43. Albérola C, Millot C (2003) Circulation in the French Mediterranean coastal zone near Marseilles: the influence of the wind and the Northern Current. Cont Shelf Res 23(6):587–610
    Article Google Scholar

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Authors and Affiliations

  1. Antenne du Laboratoire d’Océanographie et de Biogéochimie, Université de la Méditerranée et Centre National de la Recherche Scientifique (UMR 6535), BP 330, 83505, La Seyne/mer, France
    Claude Millot & Isabelle Taupier-Letage

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  1. Claude Millot
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  2. Isabelle Taupier-Letage
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Correspondence toIsabelle Taupier-Letage .

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Alain Saliot

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Millot, C., Taupier-Letage, I. (2005 ). Circulation in the Mediterranean Sea. In: Saliot, A. (eds) The Mediterranean Sea. Handbook of Environmental Chemistry, vol 5K. Springer, Berlin, Heidelberg. https://doi.org/10.1007/b107143

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