• Arhan, M., , K. J. Heywood, , and B. A. King, 1999: The deep waters from the Southern Ocean at the entry to the Argentine Basin. Deep-Sea Res, 46 , 475499.

    • Search Google Scholar
    • Export Citation
  • Bacon, S., , H. M. Snaith, , and M. J. Yelland, 2000: An evaluation of some recent batches of IAPSO standard seawater. J. Atmos. Oceanic Technol, 17 , 854861.

    • Search Google Scholar
    • Export Citation
  • Carmack, E. C., , and T. D. Foster, 1975: On the flow of water out of the Weddell Sea. Deep-Sea Res, 22 , 711724.

  • Coles, V. J., , M. S. McCartney, , D. B. Olson, , and W. M. Smethie, 1996: Changes in Antarctic Bottom Water properties in the western South Atlantic in the late 1980s. J. Geophys. Res, 101 , (C4),. 89578970.

    • Search Google Scholar
    • Export Citation
  • Dickson, A. G., 1994: Determination of dissolved oxygen in seawater by Winkler titration. World Ocean Circulation Experiment (WOCE) Hydrographic Program, Operations and Methods WMPO 91-1, 3–11.

    • Search Google Scholar
    • Export Citation
  • Foster, T. D., , and E. C. Carmack, 1976: Frontal zone mixing and Antarctic Bottom Water formation in the southern Weddell Sea. Deep-Sea Res, 23 , 301317.

    • Search Google Scholar
    • Export Citation
  • Garcia, M., , O. Lopez, , J. Puigdefabregas, , and J. Sospreda, 1997: Repeated observations of the ACC on WOCE SR1b. Int. WOCE Newslett, 29 , 1618.

    • Search Google Scholar
    • Export Citation
  • Gill, A. E., 1973: Circulation and bottom water production in the Weddell Sea. Deep-Sea Res, 20 , 111140.

  • Gordon, A. L., 1966: Potential temperature, oxygen and circulation of bottom water in the southern ocean. Deep-Sea Res, 13 , 11251138.

    • Search Google Scholar
    • Export Citation
  • Heywood, K. J., , and B. A. King, 1996: WOCE section A23 cruise report. UEA Rep. Series 1, School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom, 75 pp.

    • Search Google Scholar
    • Export Citation
  • Heywood, K. J., , and D. P. Stevens, 2000: ALBATROSS cruise report. UEA Rep. Series 6, School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom, 61 pp.

    • Search Google Scholar
    • Export Citation
  • Hogg, N. G., , and W. Zenk, 1997: Long-period changes in the bottom water flowing through Vema Channel. J. Geophys. Res, 102 , (C7),. 15 63915 646.

    • Search Google Scholar
    • Export Citation
  • Jackett, D. R., , and T. J. McDougall, 1997: A neutral density variable for the world's oceans. J. Phys. Oceanogr, 27 , 237263.

  • Kirkwood, D. S., 1995: Nutrients: Practical notes on their determination in seawater. ICES Techniques in Marine Environmental Sciences Rep. 17, International Council for the Exploration of the Seas, Copenhagen, Denmark, 25 pp.

    • Search Google Scholar
    • Export Citation
  • Locarnini, R. A., , T. Whitworth III, , and W. D. Nowlin Jr., 1993: The importance of the Scotia Sea on the outflow of Weddell Sea Deep Water. J. Mar. Res, 51 , 135153.

    • Search Google Scholar
    • Export Citation
  • Martinson, D. G., , P. D. Killworth, , and A. L. Gordon, 1982: A convective model for the Weddell Polynya. J. Phys. Oceanogr, 11 , 466488.

    • Search Google Scholar
    • Export Citation
  • Meredith, M. P., , K. E. Grose, , E. L. McDonagh, , K. J. Heywood, , R. D. Frew, , and P. F. Dennis, 1999: Distribution of oxygen isotopes in the water masses of Drake Passage and the South Atlantic. J. Geophys. Res, 104 , (C9),. 20 94920 962.

    • Search Google Scholar
    • Export Citation
  • Meredith, M. P., , R. A. Locarnini, , K. A. Van Scoy, , A. J. Watson, , K. J. Heywood, , and B. A. King, 2000: On the sources of Weddell Gyre Antarctic Bottom Water. J. Geophys. Res, 105 , (C1),. 10931104.

    • Search Google Scholar
    • Export Citation
  • Orsi, A. H., , W. D. Nowlin Jr., , and T. Whitworth III, 1993: On the circulation and stratification of the Weddell Gyre. Deep-Sea Res, 40 , 169203.

    • Search Google Scholar
    • Export Citation
  • Orsi, A. H., , T. Whitworth III, , and W. D. Nowlin Jr., 1995: On the meridional extent and fronts of the Antarctic Circumpolar Current. Deep-Sea Res, 42 , 641673.

    • Search Google Scholar
    • Export Citation
  • Peterson, R. G., , and T. Whitworth III, 1989: The subantarctic and polar fronts in relation to deep water masses through the southwestern Atlantic. J. Geophys. Res, 94 , (C8),. 10 81710 838.

    • Search Google Scholar
    • Export Citation
  • Rubython, K. E., , K. J. Heywood, , and J. M. Vassie, 2001: Interannual variability of bottom temperatures in Drake Passage. J. Geophys. Res.,. 106 , (C2),. 27792793.

    • Search Google Scholar
    • Export Citation
  • Sievers, H. A., , and W. D. Nowlin Jr., 1984: The stratification and water masses at Drake Passage. J. Geophys. Res, 89 , (C6),. 10 48910 514.

    • Search Google Scholar
    • Export Citation
  • Smith, W. H. F., , and D. T. Sandwell, 1997: Global sea floor topography from satellite altimetry and ship depth soundings. Science, 277 , 19561962.

    • Search Google Scholar
    • Export Citation
  • Thorpe, S. E., , K. J. Heywood, , and M. A. Brandon, 1999: Interannual variability in the Southern Ocean fronts near South Georgia and its effects on krill transport. Eos, Trans. Amer. Geophys. Union, 80 , 197.

    • Search Google Scholar
    • Export Citation
  • Weiss, R. F., , H. G. Östlund, , and H. Craig, 1979: Geochemical studies of the Weddell Sea. Deep-Sea Res, 26 , 10931120.

  • Whitworth, T. I. I. I., , W. D. Nowlin Jr., , A. H. Orsi, , R. A. Locarnini, , and S. G. Smith, 1994: Weddell Sea shelf water in the Bransfield Strait and Weddell–Scotia Confluence. Deep-Sea Res, 41 , 629641.

    • Search Google Scholar
    • Export Citation
  • Williams, P. J. L., , and N. W. Jenkinson, 1982: A transportable microprocessor-controlled precise Winkler titration suitable for field station and shipboard use. Limnol. Oceanogr, 25 , 576584.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 196 196 10
PDF Downloads 44 44 4

Deep and Bottom Waters in the Eastern Scotia Sea: Rapid Changes in Properties and Circulation

View More View Less
  • 1 School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
  • | 2 School of Mathematics, University of East Anglia, Norwich, United Kingdom
  • | 3 School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
© Get Permissions Rent on DeepDyve
Restricted access

Abstract

Two meridional hydrographic transects (in 1995 and 1999) across the eastern Scotia Sea are used to investigate variability in the deep and bottom waters between the South Scotia Ridge and South Georgia. There is a significant warming of the warm deep water (WDW) south of the southern boundary of the Antarctic Circumpolar Current (ACC); waters are approximately 0.1°–0.2°C warmer in 1999 than 1995. This is due mainly to raised WDW potential temperatures in the Weddell Sea being fed through to the Scotia Sea as the WDW flows northeastward in the Weddell Gyre. There is a warming of the Weddell Sea Deep Water (WSDW) of approximately 0.05°C across the whole extent of the section, and an accompanying change in salinity that maintains the potential temperature–salinity relationship. This is caused by variability in the properties of the water overflowing the South Scotia Ridge, rather than enhanced outflow of the bottom layer of the Scotia Sea or movements of the ACC fronts, and may be related to changes in the intensity of the Weddell Gyre circulation. Consideration of other works suggests that the colder WSDW of 1995 is likely to be the anomalous case, rather than the warmer WSDW of 1999. The 1999 section reveals an inflow of Lower WSDW from east of the South Sandwich Arc via the Georgia Passage; this is constrained to the south of the southern boundary, and is not apparent in the 1995 measurements. Meanders in the southern boundary at Georgia Passage are likely to play a role in controlling the inflow of Lower WSDW, although changes in the peak density of the WSDW flowing across the South Scotia Ridge may be important also, with a denser inflow from the south acting to preclude an inflow of similar density from the northeast.

*Current affiliation: Physical Sciences Division, British Antarctic Survey, Cambridge, United Kingdom.

+ Current affiliation: Southampton Oceanography Centre, Southampton, United Kingdom.

Corresponding author address: Dr. Michael P. Meredith, British Antarctic Survey, High Cross Madingley Rd., Cambridge CB3 0ET, United Kingdom. Email: mmm@bas.ac.uk

Abstract

Two meridional hydrographic transects (in 1995 and 1999) across the eastern Scotia Sea are used to investigate variability in the deep and bottom waters between the South Scotia Ridge and South Georgia. There is a significant warming of the warm deep water (WDW) south of the southern boundary of the Antarctic Circumpolar Current (ACC); waters are approximately 0.1°–0.2°C warmer in 1999 than 1995. This is due mainly to raised WDW potential temperatures in the Weddell Sea being fed through to the Scotia Sea as the WDW flows northeastward in the Weddell Gyre. There is a warming of the Weddell Sea Deep Water (WSDW) of approximately 0.05°C across the whole extent of the section, and an accompanying change in salinity that maintains the potential temperature–salinity relationship. This is caused by variability in the properties of the water overflowing the South Scotia Ridge, rather than enhanced outflow of the bottom layer of the Scotia Sea or movements of the ACC fronts, and may be related to changes in the intensity of the Weddell Gyre circulation. Consideration of other works suggests that the colder WSDW of 1995 is likely to be the anomalous case, rather than the warmer WSDW of 1999. The 1999 section reveals an inflow of Lower WSDW from east of the South Sandwich Arc via the Georgia Passage; this is constrained to the south of the southern boundary, and is not apparent in the 1995 measurements. Meanders in the southern boundary at Georgia Passage are likely to play a role in controlling the inflow of Lower WSDW, although changes in the peak density of the WSDW flowing across the South Scotia Ridge may be important also, with a denser inflow from the south acting to preclude an inflow of similar density from the northeast.

*Current affiliation: Physical Sciences Division, British Antarctic Survey, Cambridge, United Kingdom.

+ Current affiliation: Southampton Oceanography Centre, Southampton, United Kingdom.

Corresponding author address: Dr. Michael P. Meredith, British Antarctic Survey, High Cross Madingley Rd., Cambridge CB3 0ET, United Kingdom. Email: mmm@bas.ac.uk

Save