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The Upper 1000-m Slope Currents North of the South Shetland Islands and Elephant Island Based on Ship Cruise Observations

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Abstract

While the Antarctic Slope Current (ASC) has been intensively studied for the East Antarctica slope area and the Weddell Sea, its fate in the western Antarctic Peninsula (WAP) region remains much less known. Data from two cruises conducted near the South Shetland Islands (SSIs) and the Elephant Island (EI), one in austral summer of 2004 and one in austral winter of 2006, were analyzed to provide a broad picture of the circulation pattern over the continental slope of the surveyed area, and an insight into the dynamical balance of the circulation. The results indicate that southwestward currents are present over the upper slope in the study area, indicating the ASC in the WAP region. Near the Shackleton Gap (SG) north of the EI, the southwestward slope currents near the shelf break are characterized by a water mass colder and fresher than the ambient water, which produces cross-slope density gradients and then vertical shear of the along-slope (or along-isobath) velocity. The vertical shear is associated with a reversal of the along-slope current from northeastward at surface to southwestward in deeper layers, or a depth-intensification of the southwestward slope currents. The water mass with temperature and salinity characteristics similar to the observed cold and fresh water is also revealed on the southern slope of the Scotia Sea, suggesting that this cold and fresh water is originated from the Scotia Sea slope and flows southwestward through the SG. Over the shelf north of the SSIs, the cold and fresh water mass is also observed and originates mainly from the Bransfield Strait. In this area, vertical structure of the southwestward slope currents is associated with the onshore intrusion of the upper Circumpolar Deep Water that creates cross-slope density gradients.

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References

  • Ardelan, M. V., Holmhansen, O., Hewes, C. D., Reiss, C. S., Silva, N. S., Dulaiova, H., Steinnes, E., and Sakshaug, E., 2010. Natural iron enrichment around the Antarctic Peninsula in the Southern Ocean. Biogeosciences, 7 (1): 11–25.

    Article  Google Scholar 

  • Capella, J. E., Ross, R. M., Quetin, L. B., and Hofmann, E. E., 1992. A note on the thermal structure of the upper ocean in the Bransfield Strait-South Shetland Islands region. Deep Sea Research Part A. Oceanographic Research Papers, 39 (7-8): 1221–1229, DOI: 10.1016/0198-0149(92)90065-2.

    Article  Google Scholar 

  • Dong, S., Sprintall, J., Gille, S. T., and Talley, L., 2008. Southern Ocean mixed-layer depth from Argo float profiles. Journal of Geophysical Research, 113 (C6), DOI: 10.1029/2006JC004051.

    Google Scholar 

  • Flexas, M. M., Schodlok, M. P., Padman, L., Menemenlis, D., and Orsi, A. H., 2015. Role of tides on the formation of the Antarctic Slope Front at the Weddell-Scotia Confluence. Journal of Geophysical Research: Oceans, 120 (5): 3658–3680, DOI: 10.1002/2014JC010372.

    Google Scholar 

  • Frants, M., Gille, S. T., Hewes, C. D., Holm-Hansen, O., Kahru, M., Lombrozo, A., Measures, C. I., Greg Mitchell, B., Wang, H., and Zhou, M., 2013. Optimal multiparameter analysis of source water distributions in the Southern Drake Passage. Deep Sea Research Part II: Topical Studies in Oceanography, 90: 31–42, DOI: 10.1016/j.dsr2.2012.06.002.

    Article  Google Scholar 

  • Gordon, A. L., Mensch, M., Zhaoqian, D., Smethie, W. M., and Bettencourt, J., 2000. Deep and bottom water of the Bransfield Strait eastern and central basins. Journal of Geophysical Research, 105 (C5): 11337–11346.

    Article  Google Scholar 

  • Heywood, K. J., Naveira Garabato, A. C., Stevens, D. P., and Muench, R. D., 2004. On the fate of the Antarctic Slope Front and the origin of the Weddell Front. Journal of Geophysical Research: Oceans, 109: C06021.

    Article  Google Scholar 

  • Heywood, K. J., Schmidtko, S., Heuzé, C., Kaiser, J., Jickells, T. D., Queste, B. Y., Stevens, D. P., Wadley, M., Thompson, A. F., and Fielding, S., 2014. Ocean processes at the Antarctic continental slope. Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, 372 (2019): 20130047.

    Article  Google Scholar 

  • Jiang, M., Charette, M. A., Measures, C. I., Zhu, Y., and Zhou, M., 2013. Seasonal cycle of circulation in the Antarctic Peninsula and the off-shelf transport of shelf waters into southern Drake Passage and Scotia Sea. Deep Sea Research Part II Topical Studies in Oceanography, 90 (6): 15–30.

    Article  Google Scholar 

  • Locarnini, R. A., Whitworth, T., and Nowlin, W. D., 1993. The importance of the Scotia Sea on the outflow of Weddell Sea deep water. Journal of Marine Research, 51 (1): 135–153.

    Article  Google Scholar 

  • Mathiot, P., Goosse, H., Fichefet, T., Barnier, B., and Gallée, H., 2011. Modelling the seasonal variability of the Antarctic Slope Current. Ocean Science, 7 (4): 445–532.

    Article  Google Scholar 

  • Moffat, C., Owens, B., and Beardsley, R. C., 2009. On the characteristics of Circumpolar Deep Water intrusions to the west Antarctic Peninsula Continental Shelf. Journal of Geophysical Research, 114 (C5), DOI: 10.1029/2008JC004955.

    Google Scholar 

  • Naveira Garabato, A. C., Heywood, K. J., and Stevens, D. P., 2002. Modification and pathways of Southern Ocean Deep Waters in the Scotia Sea. Deep Sea Research Part I: Oceanographic Research Papers, 49 (4): 681–705, DOI: 10.1016/S0967-0637(01)00071-1.

    Article  Google Scholar 

  • Nowlin, W. D., and Klinck, J. M., 1986. The physics of the Antarctic Circumpolar Current (paper 6R0315). Reviews of Geophysics, 24 (3): 469.

    Article  Google Scholar 

  • Nowlin, W. D., and Zenk, W., 1988. Westward bottom currents along the margin of the South Shetland Island Arc. Deep Sea Research Part A. Oceanographic Research Papers, 35 (2): 269–301.

    Article  Google Scholar 

  • Orsi, A. H., Iii, T. W., and Jr, W. D. N., 1995. On the meridional extent and fronts of the Antarctic Circumpolar Current. Deep Sea Research Part I: Oceanographic Research Papers, 42 (5): 641–673.

    Article  Google Scholar 

  • Peña-Molino, B., McCartney, M. S., and Rintoul, S. R., 2016. Direct observations of the Antarctic Slope Current transport at 113°E. Journal of Geophysical Research: Oceans, 121: 7390–7407, DOI: 10.1002/2015JC011594.

    Google Scholar 

  • Padman, L., Fricker, H. A., Coleman, R., Howard, S., and Erofeeva, L., 2002. A new tide model for the Antarctic ice shelves and seas. Annals of Glaciology, 34 (1): 247–254.

    Article  Google Scholar 

  • Quetin, L. B., and Ross, R. M., 1984. Depth distribution of developing Euphausia superba embryos, predicted from sinking rates. Marine Biology, 79 (1): 47–53.

    Article  Google Scholar 

  • Quetin, L. B., and Ross, R. M., 1984. School composition of the Antarctic krill Euphausia superba in the waters west of the Antarctic Peninsula in the austral summer of 1982. Journal of Crustacean Biology, 4 (5): 96–106.

    Article  Google Scholar 

  • RDI, 1989. Acoustic Doppler Current Profilers Principles of Operation-A Practical Primer: RD Instruments. San Diego, Calif., 36pp.

  • Ross, R. M., Hofmann, E. E., and Quetin, L. B., 2013. Water Mass Distribution and Circulation West of the Antarctic Peninsula and Including Bransfield Strait. American Geophysical Union.

    Google Scholar 

  • Savidge, D. K., and Amft, J. A., 2009. Circulation on the West Antarctic Peninsula derived from 6 years of shipboard ADCP transects. Deep Sea Research Part I: Oceanographic Research Papers, 56 (10): 1633–1655.

    Article  Google Scholar 

  • Selph, K. E., Apprill, A., Measures, C. I., Hatta, M., Hiscock, W. T., and Brown, M. T., 2013. Phytoplankton distributions in the Shackleton Fracture Zone/Elephant Island region of the Drake Passage in February-March 2004. Deep Sea Research Part II: Topical Studies in Oceanography, 90: 55–67, DOI: 10.1016/j.dsr2.2013.01.030.

    Article  Google Scholar 

  • Shi, J., Sun, Y., Jiao, Y., Hao, G., Wang, M., 2016. Water masses and exchanges in the region around the northern tip of the Antarctic Peninsula observed in summer 2011/2012. Chinese Journal of Polar Research, 28 (1): 67–79 (in Chinese).

    Google Scholar 

  • Siegel, V., Reiss, C. S., Dietrich, K. S., Haraldsson, M., and Rohardt, G., 2013. Distribution and abundance of Antarctic krill (Euphausia superba) along the Antarctic Peninsula. Deep Sea Research Part I: Oceanographic Research Papers, 77: 63–74, DOI: 10.1016/j.dsr.2013.02.005.

    Article  Google Scholar 

  • Stewart, A. L., and Thompson, A. F., 2015. Eddy-mediated transport of warm Circumpolar Deep Water across the Antarctic Shelf Break. Geophysical Research Letters, 42 (2): 432–440, DOI: 10.1002/2014GL062281.

    Article  Google Scholar 

  • Stewart, A. L., and Thompson, A. F., 2016. Eddy generation and jet formation via dense water outflows across the Antarctic continental slope. Journal of Physical Oceanography, DOI: 10.1175/JPO-D-16-0145.1.

    Google Scholar 

  • Thompson, A. F., Heywood, K. J., Thorpe, S. E., Renner, A. H., and Trasviña, A., 2009. Surface circulation at the tip of the Antarctic Peninsula from drifters. Journal of Physical Oceanography, 39 (1): 3–26.

    Article  Google Scholar 

  • Youngs, M. K., Thompson, A. F., Flexas, M. M., and Heywood, K. J., 2015. Weddell sea export pathways from surface drifters. Journal of Physical Oceanography, 45 (4): 1068–1085, DOI: 10.1175/JPO-D-14-0103.1.

    Article  Google Scholar 

  • Zhou, M., Zhu, Y., Dorland, R. D., and Measures, C. I., 2010. Dynamics of the current system in the southern Drake Passage. Deep Sea Research Part I: Oceanographic Research Papers, 57 (9): 1039–1048.

    Article  Google Scholar 

  • Zhou, M., Zhu, Y., Measures, C. I., Hatta, M., Charette, M. A., Gille, S. T., Frants, M., Jiang, M., and Mitchell, B. G., 2013. Winter mesoscale circulation on the shelf slope region of the southern Drake Passage. Deep Sea Research Part II: Topical Studies in Oceanography, 90: 4–14.

    Article  Google Scholar 

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Acknowledgements

This work was funded by the National Natural Science Foundation of China (No. 41406006). Y. Z was sponsored by Shanghai Sailling Program (No. 15FY1406400). We would like to acknowledge the hard work by crews of the A.S.R.V.L.M. Gould and R.V.I.B.N.B. Palmer cruises. We would also like to acknowledge the anonymous reviewers for improving the quality of this manuscript.

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  1. Institute of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China

    Guangqian Du, Zhaoru Zhang, Meng Zhou, Yiwu Zhu & Yisen Zhong

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  1. Guangqian Du
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  2. Zhaoru Zhang
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  3. Meng Zhou
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  4. Yiwu Zhu
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Correspondence to Zhaoru Zhang.

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Du, G., Zhang, Z., Zhou, M. et al. The Upper 1000-m Slope Currents North of the South Shetland Islands and Elephant Island Based on Ship Cruise Observations. J. Ocean Univ. China 17, 420–432 (2018). https://doi.org/10.1007/s11802-018-3353-9

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  • DOI: https://doi.org/10.1007/s11802-018-3353-9

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