Abstract
Global ocean circulation models usually lack an adequate consideration of high-latitude processes due to a limited model domain or insufficient resolution. Without the processes in key areas of the global thermohaline circulation, the characteristics and flow of deep and bottom waters cannot be modeled realistically. In this study, a high-resolution (~20 km) ocean model focused on the Weddell Sea sector of the Southern Ocean is combined with a low-resolution (2° × 2°) global ocean model applying the state estimation technique. Temperature, salinity, and velocity data on two Weddell Sea sections from the regional model are used as constraints for the large-scale model in addition to satellite altimetry and sea-surface temperatures. The differences between the model with additional constraints and without document that the Weddell Sea circulation exerts significant influence on the course of the Antarctic Circumpolar Current with consequences for Southern Ocean water mass characteristics and the spreading of deep and bottom waters in the South Atlantic. Furthermore, a warming trend in the period 1993–2001 was found in the Weddell Sea and adjacent basins in agreement with float measurements in the upper Southern Ocean. Teleconnections to the North Atlantic are suggested but need further studies to demonstrate their statistical significance.
Similar content being viewed by others
References
Assmann KM, Timmermann R (2005) Variability of dense water formation in the Ross Sea. Ocean Dyn (in press)
Beckmann A, Hellmer HH, Timmermann R (1999) A numerical model of the Weddell Sea: large-scale circulation and water mass distribution. J Geophys Res 104:23374–23391
Beckmann A, Timmermann R (2001) Circumpolar influences on the Weddell Sea: indication of an Antarctic Circumpolar Coastal Wave. J Clim 14:3785–3792
Brix H, Gerdes R (2003) NADW and AABW: Their interaction and influence on the variability of the global ocean circulation. J Geophys Res 108. DOI 10.1029/2002JC001335
Bryden HL, Imawaki S (2001) Ocean heat transport. In: Siedler G, Church J, Gould J (eds) Ocean Circulation and Climate, Academic Press. Intern Geophys Ser 77:455–474
Carmack EC (1977) Water characteristics of the Southern Ocean south of the Polar Front. In: Angel M (ed) A voyage of discovery—George Deacon 70th Anniversary Volume, Pergamon Press, New York, pp 15–41
CLS: SHOM98.2 mean sea surface http://www.cls.fr/html/oceano/projets/mss/cls_shom_en.html
Coles VJ, McCartney MS, Olson DB, Smethie Jr WM (1996) Changes in Antarctic bottom water properties in the western South Atlantic in the late 1980s. J Geophys Res 101:8957–8970
Emery WJ, Meincke J (1986) Global water masses: summary and review. Oceanol Acta 9:383–391
Fahrbach E, Rohardt G, Schröder M, Strass V (1994) Transport and structure of the Weddell Gyre. Ann Geophys 12:840–855
Gates, WL, Nelson AB (1975) A new (revised) tabulation of the Scripps topography on a 1 degree global grid. Part II: Ocean depths. Tech Rep R-1277-1-ARPA, The Rand Corporation, Santa Monica
GfZ: EIGEN-GRACE01S geoid. http://op.gfz-potsdam.de/grace/index_GRACE.html
Gille ST (2002) Warming of the Southern Ocean since the 1950s. Science 295:1275–1277
Gordon AL, Visbeck M, Huber B (2001) Export of Weddell Sea deep and bottom water. J Geophys Res 106:9005–9018
Hellmer HH, Beckmann A (2001) The Southern Ocean: a ventilation contributor with multiple sources. Geophys Res Lett 28:2927–2930
Hellmer HH (2004) Impact of Antarctic ice shelf basal melting on sea ice and deep ocean properties. Geophys Res Lett 31:L10307. DOI10.1029/2004GL19506
Locarnini RA, Whitworth III T, Nowlin Jr WD (1993) The importance of the Scotia Sea on the outflow of Weddell Sea deep water. J Mar Res 51:135–153
Maier-Reimer E, Mikolajewicz U (1991) The Hamburg Large Scale Geostrophic Ocean General Circulation Model (Cycle 1). Tech Rep No. 2. Deutsches Klimarechenzentrum, Hamburg
Maier-Reimer E, Mikolajewicz U, Hasselmann K (1993) Mean circulation of the Hamburg LSG OGCM and its sensitivity to the thermohaline surface forcing. J Phys Oceanogr 23:731–757
Manabe S, Stouffer RJ, Spelman MJ, Bryan K (1991) Transient response of a coupled ocean-atmosphere model to gradual changes of atmospheric CO2. Part 1: annual mean response. J Clim 4:785–818
Meredith MP, Naveira Garabato AC, Stevens DP, Heywood KJ, Sanders RJ (2001) Deep and bottom waters in the eastern Scotia Sea: rapid changes in properties and circulation. J Phys Oceanogr 31:2157–2168
Muench RD, Hellmer HH (2002) The international DOVETAIL program. Deep-Sea Res II 49:4711–4714
Naveira Garabato AC, Heywood KJ, Stevens DP (2002a) Modification and pathways of Southern Ocean deep waters in the Scotia Sea. Deep-Sea Res 49:681–705
Naveira Garabato AC, McDonagh EL, Stevens DP, Heywood KJ, Sanders RJ (2002b) On the export of Antarctic Bottom Water from the Weddell Sea. Deep-Sea Res II 49:4715–4742
Nowlin Jr WD, Zenk W (1988) Westward bottom currents along the margin of the South Shetland Island arc. Deep-Sea Res 35:269–301
Olbers D, Wübber C (1991) The role of wind and buoyancy forcing of the Antarctic Circumpolar Current. In: Latif M (ed) Strategies for future climate research, MPI, Hamburg, pp 161–192
Orsi AH, Whitworth III T, Nowlin Jr WD (1995) On the meridional extent and fronts of the Antarctic Circumpolar Current. Deep-Sea Res 42:641–673
Orsi AH, Johnson GC, Bullister JL (1999) Circulation, mixing, and production of Antarctic Bottom Water. Prog Oceanogr 43:55–109
Reynolds RW, Rayner NA, Smith TM, Stokes DC, Wang W (2002) An improved in situ and satellite SST analysis for climate. J Clim 15:1609–1625
Robertson R, Visbeck M, Gordon AL (2002) Long-term potential temperature trends in the deep waters of the Weddell Sea. Deep-Sea Res II 49:4791–4806
Rubython KE, Heywood KJ, Vassie JM (2001) Interannual variability of bottom temperatures in Drake Passage. J Geophys Res 106:2779–2793
Schodlok MP, Hellmer HH, Beckmann A (2002) On the transport, variability, and origin of dense water masses crossing the South Scotia Ridge. Deep-Sea Res II 49:4807–4825
Schröder M, Fahrbach E (1999) On the structure and the transport in the eastern Weddell Gyre. Deep-Sea Res II 46:501–527
Schröder M, Hellmer HH, Absy JM (2002) On the near-bottom variability in the northwestern Weddell Sea. Deep-Sea Res II 49:4767–4790
Sloyan BM, Rintoul SR (2001) The Southern Ocean limb of the global deep overturning circulation. J Phys Oceanogr 31:143–173
Staneva J, Wenzel M, Schröter J (2002) Oceanic state during 1993-1999 determined by 4D Var data assimilation. WOCE Int Newslett 42:11–13
Storch H von, Zwiers FW (1999) Statistical Analysis in Climate Reseach. Cambridge University Press, Cambridge
Timmermann R, Beckmann A, Hellmer HH (2002) Simulations of ice-ocean dynamics in the Weddell Sea 1. Model configuration and validation. J Geophys Res 107. DOI10.1029/2000JC000741
Wenzel M, Schröter J, Olbers D (2001) The annual cycle of the global ocean circulation as determined by 4D VAR data assimilation. Prog Oceanogr 48:73–119
Wenzel M, Schröter J (2002) Assimilation of TOPEX/POSEIDON data in a global ocean model: differences in 1995–1996. Phys Chem Earth 27:1433–1437
Whitworth III T, Nowlin Jr WD, Locarnini RA, Smith SG (1994) Weddell Sea shelf water in the Bransfield Strait and Weddell-Scotia Confluence. Deep-Sea Res 41:629–641
Whitworth III T, Orsi AH, Kim SJ, Nowlin Jr WD, Locarnini RA (1998) Water masses and mixing near the Antarctic slope front. In: Jacobs SS, Weiss R (eds) Ocean, ice, and atmosphere: interactions at the Antarctic continental margin. Antarc Res Ser 75:1–27
Wijffels SE (2001) Ocean transport of fresh water. In: Siedler G, Church J, Gould J (eds) Ocean circulation and climate. Academic Press. Intern Geophys Ser 77:475-488
Wüst G (1935) Schichtung und Zirkulation des atlantischen Ozeans. Das Bodenwasser und die Stratosphäre. Wiss. Ergeb. dtsch. atlant. Exped. Meteor 1925-27 6:1–288
Yuan X, Martinson DG (2001) The Antarctic dipole and its predictability. Geophys Res Lett 28:3609–3612
Acknowledgments
Thanks to S. Esselborn for providing the TOPEX/Poseidon altimeter data, to U. Mikolajewicz and two anonymous reviewers for careful reading and a constructive evaluation, and to the editors of Ocean Dynamics for a courageous handling of the manuscript.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Hellmer, H.H., Schodlok, M.P., Wenzel, M. et al. On the influence of adequate Weddell Sea characteristics in a large-scale global ocean circulation model. Ocean Dynamics 55, 88–99 (2005). https://doi.org/10.1007/s10236-005-0112-4
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10236-005-0112-4