Skip to main content

Advertisement

SpringerLink
Log in

Modification by lateral mixing of the Warm Deep Water entering the Weddell Sea in the Maud Rise region

  • Published:
Ocean Dynamics Aims and scope Submit manuscript

Abstract

Deep water originating in the North Atlantic is transported across the Antarctic Circumpolar Current by eddies and, after circumnavigating of the Antarctic, enters the Weddell Gyre south of Africa. As it does so, it rises up from mid-depth towards the surface. The separate temperature and salinity maxima, the Upper and Lower Circumpolar Deep Waters, converge to form the Warm Deep Water. Cores of this water mass on the southern flank of the eastern Weddell Gyre show a change in characteristic as they flow westward in the Lazarev Sea. Observations have been made along four meridional sections at 3° E, 0°, 3° W and 6° W between 60 and 70° S during the Polarstern Cruise ANTXXIII/2 in 2005/2006. These show that a heterogeneous series of warm and salty cores entering the region from the east both north and south of Maud Rise (65° S, 3° W) gradually merge and become more homogeneous towards the west. The gradual reduction in the variance of potential temperature on isopycnals is indicative of isopycnic mixing processes. A multiple regression technique allows diagnosis of the eddy diffusivities and, thus, the relative importance of isopycnic and diapycnic mixing. The method shows that the isopycnic diffusivity lies in the range 70–140 m2 s−1 and the diapycnic diffusivity reaches about 3 × 10−6 m2 s−1. Scale analysis suggests that isopycnic diffusion dominates over diapycnic diffusion in the erosion of the Warm Deep Water cores.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10

Similar content being viewed by others

References

  • Akimoto K (2006) Thermobaric deep convection, baroclinic instability, and their roles in vertical heat transport around Maud Rise in the Weddell Sea. J Geophys Res 111:C09027, 10 pp. doi:10.1029/2005JC003284

  • Bagriantsev NV, Gordon AL, Huber BA (1989) Weddell Gyre: temperature maximum stratum. J Geophys Res 94:8331–8334

    Article  Google Scholar 

  • Beckmann A, Hellmer HH, Timmermann R (1999) A numerical model of the Weddell Sea: large-scale circulation and water mass distribution. J Geophys Res 104:23375–23391

    Article  Google Scholar 

  • Beckmann A, Timmermann R, Pereira AF, Mohn C (2001) The effect of flow at Maud Rise on the sea-ice cover—numerical experiments. Ocean Dyn 52:11–25

    Article  Google Scholar 

  • Bersch M, Becker GA, Frey H, Koltermann KP (1992) Topographic effects of the Maud Rise on the stratification and circulation of the Weddell Gyre. Deep-Sea Res 39:303–331

    Article  Google Scholar 

  • Brennecke W (1921) Die ozeanographischen Arbeiten der Deutschen Antarktischen expedition 1911–1912. Aus Arch Dtsch Seewetterwarte 39:216

    Google Scholar 

  • Carmack EC (1974) A quantitative characterisation of water masses in the Weddell Sea during summer. Deep-Sea Res 21:431–443

    Google Scholar 

  • Cisewski B, Strass VH, Prandke H (2005) Upper-ocean vertical mixing in the Antarctic polar front zone. Deep Sea Res II 52:1087–1108. doi:10.1016/j.dsr2.2005.01.010

    Article  Google Scholar 

  • Cisewski B, Strass VH, Losch M, Prandke H (2008) Mixed layer analysis of a mesoscale eddy in the Antarctic Polar Front Zone. J Geophys Res 113:C05017. doi:10.1029/2007JC004372

    Article  Google Scholar 

  • Comiso JC, Gordon AL (1987) Recurring polynyas over the Cosmonaut Sea and the Maud Rise. J Geophys Res 92:2819–2833

    Article  Google Scholar 

  • Cunningham SA, Haine TWN (1995) Labrador Sea Water in the Eastern North Atlantic. Part II: mixing dynamics and the advective–diffusive balance. J Phys Oceanogr 25:666–678

    Article  Google Scholar 

  • D’Asaro EA, Morehead MD (1991) Internal waves and velocity fine structure in the Arctic Ocean. J Geophys Res 96:12725–12738

    Article  Google Scholar 

  • D’Asaro EA, Morison JH (1992) Internal waves and mixing in the Arctic Ocean. Deep-Sea Res 39(Suppl 2):S459–S484

    Article  Google Scholar 

  • Deacon GER (1933) A general account of the hydrology of the South Atlantic Ocean. Discov Rep VII:171–238

    Google Scholar 

  • Deacon GER (1979) The Weddell Gyre. Deep-Sea Res 26A:981–995

    Article  Google Scholar 

  • de Steur L, Holland DM, Muench RD, McPhee MG (2007) The warm-water ‘Halo’ around Maud Rise: properties, dynamics and impact. Deep Sea Res I 54:871–896. doi:10.1016/j.dsr.2007.03.009

    Article  Google Scholar 

  • Fahrbach E, Rohardt G, Schröder M, Strass V (1994) Transport and structure of the Weddell Gyre. Ann Geophysicae 12:840–855

    Article  Google Scholar 

  • Fahrbach E, Hoppema M, Rohardt G, Schröder M, Wisotzki A (2004) Decadal-scale variations of water mass properties in the deep Weddell Sea. Ocean Dyn 54:77–91. doi:10.1007/s10236-003-0082-3

    Article  Google Scholar 

  • Fahrbach E, Hoppema M, Rohardt G, Schröder M, Wisotzki A (2006) Causes of deep-water variation: comment on the paper by L.H. Smedsrud ‘Warming of the deep water in the Weddell Sea along the Greenwich Meridian: 1977–2001’. Deep Sea Res I 53:574–577. doi:10.1016/j.dsr.2005.12.003

    Article  Google Scholar 

  • Gill AE (1973) Circulation and bottom water formation in the Weddell Sea. Deep-Sea Res 20:111–140

    Google Scholar 

  • Gordon AL (1978) Deep Antarctic convection west of Maud Rise. J Phys Oceanogr 8:600–612

    Article  Google Scholar 

  • Gordon AL, Molinelli E, Baker T (1978) Large-scale relative dynamic topography of the Southern Ocean. J Geophys Res 83:3023–3032

    Article  Google Scholar 

  • Gouretski VV, Danilov AI (1993) Weddell Gyre: structure of the eastern boundary. Deep Sea Res I 40:561–582

    Article  Google Scholar 

  • Green JSA (1970) Transfer properties of the large-scale eddies and the general circulation of the atmosphere. Q J R Meteorol Soc 96:157–185

    Article  Google Scholar 

  • Hibbert A, Leach H, Strass V, Cisewski B (2009) Mixing in cyclonic eddies in the Antarctic circumpolar current. J Mar Res 67:1–23. doi:10.1357/002224009788597935

    Article  Google Scholar 

  • Holland DM (2001) Explaining the Weddell Polynya—a large ocean eddy shed at Maud Rise. Science 292:1697–1700

    Article  Google Scholar 

  • Iudicone D, Speich S, Madec G, Blanke B (2008) The global conveyor belt from a Southern Ocean perspective. J Phys Oceanogr 38:1401–1425

    Article  Google Scholar 

  • Killworth PD (1997) On the parameterization of eddy transfer. Part I: theory. J Mar Res 55:1171–1197

    Article  Google Scholar 

  • Killworth PD (1998) On the parameterization of eddy transfer. Part II: tests with a channel model. J Mar Res 56:349–374

    Article  Google Scholar 

  • Killworth PD, Smith JM (1984) A one-and-a-half dimensional model of the Arctic halocline. Deep-Sea Res 31:271–293

    Article  Google Scholar 

  • Klatt O, Fahrbach E, Hoppema M, Rohardt G (2005) The transport of the Weddell Gyre across the prime meridian. Deep Sea Res II 52:513–528. doi:10.1016/j.dsr2.2004.12.015

    Article  Google Scholar 

  • Ledwell JR, Watson AJ, Law CS (1998) Mixing of a tracer in the pycnocline. J Geophys Res 103:21499–21529

    Article  Google Scholar 

  • Ledwell JR, Montgomery ET, Polzin KL, St Laurent LC, Schmitt RW, Toole JM (2000) Evidence for enhanced mixing over rough topography in the abyssal ocean. Nature 403:179–182

    Article  Google Scholar 

  • Lenn YD, Wiles PJ, Torres-Valdes S, Abrahamsen EP, Rippeth TP, Simpson JH, Bacon S, Laxon SW, Polyakov I, Ivanov V, Kirillov S (2009) Vertical mixing at intermediate depths in the Arctic boundary current. Geophys Res Lett 36:L05601. doi:10.1029/2008GL036792

    Article  Google Scholar 

  • Lynn RJ, Reid JL (1968) Characteristics and circulation of deep and abyssal waters. Deep-Sea Res 15:577–598

    Google Scholar 

  • Marshall JC (1981) On the parameterization of geostrophic eddies in the ocean. J Phys Oceanogr 11:257–271

    Article  Google Scholar 

  • McPhee MG, Ackley SF, Guest P, Huber BA, Martinson DG, Morison JH, Muench RD, Padman L, Stanton TP (1996) The Antarctic zone flux experiment. Bull Am Meteorol Soc 77:1221–1232

    Article  Google Scholar 

  • McPhee MG (2000) Marginal thermobaric stability in the ice-covered upper ocean over Maud Rise. J Phys Oceanogr 30:2710–2722

    Article  Google Scholar 

  • McPhee MG, Kottmeier C, Morison JH (1999) Ocean heat flux in the Central Weddell Sea during winter. J Phys Oceanogr 29:1166–1179

    Article  Google Scholar 

  • McWilliams JC (1985) Submesoscale, coherent vortices in the ocean. Rev Geophys 23:165–182

    Article  Google Scholar 

  • Mosby H (1934) The waters of the Atlantic Antarctic Ocean. Scientific results of the Norwegian Antarctic expeditions 1927–1928, instituted and financed by Consul Lars Christensen 1(11) Det Norske Videnskaps-Akademi i Oslo, p 131

  • Muench RD, Morison JH, Padman L, Martinson D, Schlosser P, Huber B, Hohmann R (2001) Maud Rise revisited. J Geophys Res 106:2424–2440

    Article  Google Scholar 

  • Naveira Garabato AC, Oliver KIC, Watson AJ and Messias M-J (2004a) Turbulent diapycnal mixing in the Nordic Seas. J Geophys Res 109:C12010, 9 pp. doi:10.1029/2004JC002411

  • Naveira Garabato AC, Polzin KL, King BA, Heywood KJ, Visbeck M (2004b) Widespread intense turbulent mixing in the Southern Ocean. Science 303:210–213. doi:10.1126/science.1090929

    Article  Google Scholar 

  • Naveira Garabato AC, Stevens DP, Watson AJ, Roether W (2007) Short-circuiting of the overturning circulation in the Antarctic circumpolar current. Nature 447:194–197. doi:10.1038/nature05832

    Article  Google Scholar 

  • Okubo A (1971) Oceanic diffusion diagrams. Deep-Sea Res 18:789–802

    Google Scholar 

  • Orsi AH, Nowlin WD Jr, Whitworth T III (1993) On the circulation and stratification of the Weddell Gyre. Deep Sea Res I 40:169–203

    Article  Google Scholar 

  • Padman L, Fricker HA, Coleman R, Howard S, Erofeeva L (2002) A new tide model for the Antarctic ice shelves and seas. Ann Glaciol 34:247–254

    Article  Google Scholar 

  • Polzin KL, Toole JM, Ledwell JR, Schmitt RW (1997) Spatial variability of turbulent mixing in the Abyssal Ocean. Science 276:93–96

    Article  Google Scholar 

  • Rainville L, Winsor P (2008) Mixing across the Arctic Ocean: microstructure observations during the Beringia 2005 expedition. Geophys Res Lett 35:L08606. doi:10.1029/2008GL033532

    Article  Google Scholar 

  • Schröder M, Fahrbach E (1999) On the structure and transport of the eastern Weddell Gyre. Deep Sea Res II 46:501–527

    Article  Google Scholar 

  • Seabrooke JM, Hufford GL, Elder RB (1971) Formation of Antarctic Bottom Water in the Weddell Sea. J Geophys Res 76:2164–2178

    Article  Google Scholar 

  • Smedsrud LH (2005) Warming of the deep water in the Weddell Sea along the Greenwich Meridian: 1977–2001. Deep Sea Res I 52:241–258. doi:10.1016/j.dsr.2004.10.004

    Article  Google Scholar 

  • Smedsrud LH (2006) Causes of deep-water variations: reply to comment by E. Fahrbach, M. Hoppema, G. Rohardt, M. Schröder and A. Wisotzki. Deep Sea Res I 53:578–580. doi:10.1016.j.dsr.2005.12.010

    Article  Google Scholar 

  • Smith KS (2007) The geography of linear baroclinic instability in Earth’s oceans. J Mar Res 65:655–683

    Article  Google Scholar 

  • Smith KS, Marshall JC (2009) Evidence for enhanced eddy mixing at middepth in the Southern Ocean. J Phys Oceanogr 39:50–69

    Article  Google Scholar 

  • Strass V (ed) (2007) The expedition ANTARKTIS-XXIII/2 of the research vessel “Polarstern” in 2005/2006. Berichte zur Polar-und Meeresforschung/Reports on Polar and Marine Research 568, p 138

  • Visbeck M, Marshall J, Haine T, Spall M (1997) Specification of eddy transfer coefficients in coarse-resolution ocean circulation models. J Phys Oceanogr 27:381–402. doi:1520-1997)027/1520-0485(1997)027<0381:SOETCI>2.0.CO;2

    Article  Google Scholar 

  • Wallace DWR, Moore RM, Jones EP (1987) Ventilation of the Arctic Ocean cold halocline: rates of diapycnal and isopycnal transport, oxygen utilisation, and primary production inferred using chlorofluoromethane distributions. Deep-Sea Res 34:1957–1979

    Article  Google Scholar 

Download references

Acknowledgements

We gratefully acknowledge the help and support of the captain and crew of Polarstern and our fellow scientists on board. HL’s participation in the cruise was supported by a travel grant from the Royal Society. The Bundesministerium für Bildung und Forschung LAKRIS programme provided salary and travel for BC in a project led by Prof. M. Rhein at the Institute for Environmental Physics at the University of Bremen (Grant Reference LAKRIS 03F0400B).

Author information

Authors and Affiliations

  1. Department of Earth and Ocean Sciences, University of Liverpool, 4 Brownlow Street, Liverpool, L69 3GP, UK

    Harry Leach

  2. Alfred-Wegener-Institut für Polar- und Meeresforschung, Postfach 12 01 61, 27515, Bremerhaven, Germany

    Volker Strass & Boris Cisewski

  3. Institut für Umweltphysik, Universität Bremen, Postfach 33 04 40, 28334, Bremerhaven, Germany

    Boris Cisewski

Authors
  1. Harry Leach
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Volker Strass
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Boris Cisewski
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Harry Leach.

Additional information

Responsible Editor: Karen J. Heywood

Rights and permissions

Reprints and permissions

About this article

Cite this article

Leach, H., Strass, V. & Cisewski, B. Modification by lateral mixing of the Warm Deep Water entering the Weddell Sea in the Maud Rise region. Ocean Dynamics 61, 51–68 (2011). https://doi.org/10.1007/s10236-010-0342-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10236-010-0342-y

Keywords

Search

Navigation