OSCILLATIONS IN THE JET STRUCTURE OF THE ANTARCTIC CIRCUMPOLAR CURRENT SOUTH OF AFRICA ACCORDING TO SATELLITE ALTIMETRY DATA: TIME SERIES CALCULATION AND AVERAGE CHARACTERISTICS

Authors

  • R. Yu. Tarakanov Shirshov Institute of Oceanology, Russian Academy of Sciences

DOI:

https://doi.org/10.29006/1564-2291.JOR-2025.53(3).2

Keywords:

Dynamic topography, satellite altimetry, jets, Antarctic Circumpolar Current, long-term fluctuations

Abstract

As part of the task of studying oscillations in the meridional shift of the jet structure and changes in the intensity of currents in the Antarctic Circumpolar Current zone south of Africa (9.875°W–25.125° E) according to absolute dynamic topography (ADT) data published on the website: http://marine.copernicus.eu, the procedure for calculating time series of these parameters of currents with a ten-day discreteness is described. In this case, the jet structure is understood as the alternation in the meridional direction of zones of increased and decreased values of the absolute dynamic topography (ADT) gradient modulus, |∇ζ|. For the period of satellite altimetry observations 1993–2018, a comparison was made of series calculated for the entire sector without division into narrow meridional bands and with division and subsequent averaging over a set of these bands. It is shown that these series constructed in two different ways can either differ significantly or be almost identical to each other. In addition, a calculation was made of the zonal distributions of some characteristics of the series that are essential for spectral analysis: root mean square deviation, the share of a long-term linear trend and the share of longterm oscillations in the total variance of the series.

References


  1. Bristow, L. A., W. Mohr, S. Ahmerkamp, and M. M. M. Kuypers, 2017: Nutrients that limit growth in the ocean. Curr. Biol., 27 (11), R474–R478, https://doi.org/10.1016/j.cub.2017.03.030.

  2. Burkov, V. A., 1994: Antarctic jets. Oceanology, 34 (2), 169–177.

  3. Chapman, C. C. and J.-B. Sallée, 2017: Isopycnal mixing suppression by the Antarctic Circumpolar Current and the Southern Ocean meridional overturning circulation. J. Phys. Oceanogr., 47 (8), 2023–2045, https://doi.org/10.1175/JPO-D-16-0263.1.

  4. Chapman, C. C., M. A. Lea, A. Meyer, J.-B. Sallée, and M. Hindell, 2020: Defining Southern Ocean fronts and their influence on biological and physical processes in a changing climate. Nat. Clim. Change, 10, 210–219, https://doi.org/10.1038/s41558-020-0705-4.

  5. Freeman, N. M., N. S. Lovenduski, and P. R. Gent, 2015: Temporal variability in the Antarctic Polar Front. J. Geophys. Res. Oceans, 121, 7263–7276, https://doi.org/10.1002/2016JC012145.

  6. Jousset, S., S. S. Mulet, E. Greiner, J. Wilkin, L. Vidar, L. Chafik, R. Raj, A. Bonaduce, N. Picot, and G. Dibarboure, 2023: New Global Mean Dynamic Topography CNES-CLS22 Combining Drifters, Hydrography Profiles and High Frequency Radar Data. ESS Open Archive, 03 December 2023, https://doi.org/.10.22541/essoar.170158328.85804859/v1.

  7. Klocker, A., 2018: Opening the window to the Southern Ocean: the role of jet dynamics. Sci. Adv., 4, eaao4719, https://doi.org/10.1126/sciadv.aao4719.

  8. Koshlyakov, M. N. and R. Yu. Tarakanov, 2011: Water transport across the Subantarctic Front and the Global Ocean Conveyer Belt. Oceanology, 51 (5), 721–735, https://doi.org/10.1134/S0001437011050110.

  9. Naveira Garabato, A. C., R. Ferrari, and K. L. Polzin, 2011: Eddy stirring in the Southern Ocean. J. Geophys. Res. Oceans, 116, C09019, https://doi.org/10.1029/2010JC006818.

  10. Orsi, A. H., Whitworth Th. III, and W. D. Nowlin Jr., 1995: On the meridional extent and fronts of the Antarctic Circumpolar Current. Deep-Sea Res., 42 (5), 641–673, https://doi.org/10.1016/0967-0637(95)00021-W.

  11. Palter, J. B., J. L. Sarmiento, I. Marinov, and N. Gruber, 2013: Large-Scale, Persistent Nutrient Fronts of the World Ocean: Impacts on Biogeochemistry in Chemical Oceanography of Frontal Zones (ed. Belkin I. M.), Springer, 25–62, https://doi.org/10.1007/698_2013_241.

  12. Sokolov, S. and S. R. Rintoul, 2007: Multiple Jets of the Antarctic Circumpolar Current South of Australia. J. Phys. Oceanogr., 37 (5), 1394–1412, https://doi.org/10.1175/JPO3111.1.

  13. Sokolov, S. and S. R. Rintoul, 2009a: The circumpolar structure and distribution of the Antarctic Circumpolar Current fronts. Part А: Mean circumpolar paths. J. Geophys. Res., 114 (C11018), https://doi.org/10.1029/2008JC005108.

  14. Sokolov, S., and S. R. Rintoul, 2009b: The circumpolar structure and distribution of the Antarctic Circumpolar Current fronts. Part B: Variability and relationship to sea surface height. J. Geophys. Res., 114 (C11019), https://doi.org/10.1029/2008JC005248.

  15. Tarakanov, R. Yu., 2021: Long-term linear meridional shift of the jet structure of the Antarctic Circumpolar Current south of Africa. Oceanology, 61 (6), 815–829, https://doi.org/10.1134/S000143702106031X.

  16. Tarakanov, R. Yu., 2023a: Seasonal meridional shift of the jet structure of the Antarctic Circumpolar Current south of Africa. Oceanology, 63 (2), 157–173, https://doi.org/10.1134/S0001437023010150.

  17. Tarakanov, R. Yu., 2023b: Comparative analysis of jet detection methods on the basis of satellite altimetry data on the example of the sector of the Antarctic Circumpolar Current south of Africa. Oceanology, 63 (Suppl. 1), S23–S41, https://doi.org/10.1134/S0001437023070202.

  18. Tarakanov, R. Yu., 2024: Long-term linear meridional shift of the jet structure of the Antarctic Circumpolar Current south of Africa based on satellite altimetry data: Zonal Distribution. Oceanology, 64 (6), 784–799, https://doi.org/10.1134/S0001437024700553.

  19. Tarakanov, R. Yu. and A. M. Gritsenko, 2014a: The frontal and jet structure south of Africa based on the data of the SR02 section in December of 2009. Oceanology, 54 (4), 401–413, https://doi.org/10.1134/S0001437014030138.

  20. Tarakanov, R. Yu. and A. M. Gritsenko, 2014b: Fine-jet structure of the Antarctic Circumpolar Current south of Africa. Oceanology, 54 (6), 677–687, https://doi.org/10.1134/S0001437014050130.

  21. Tarakanov, R. Yu. and A. M. Gritsenko, 2018: Jets of the Antarctic Circumpolar Current in the Drake Passage based on hydrographic section data. Oceanology, 58 (4), 503–516, https://doi.org/10.1134/S0001437018040100.

  22. Thompson, A. F. and J.- B. Sallée, 2012: Jets and topography: jet transitions and the impact on transport in the Antarctic circumpolar current. J. Phys. Oceanogr., 42 (6), 956–972, https://doi.org/10.1175/JPO-D-11-0135.1.

  23. Venables, H. and C. M. Moore, 2010: Phytoplankton and light limitation in the Southern Ocean: learning from high-nutrient, high-chlorophyll areas. J. Geophys. Res. Oceans, 115 (2), https://doi.org/10.1029/2009JC005361.

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Published

2025-09-21

Issue

Vol. 53 No. 3 (2025): Journal of Oceanological Research

Section

Ocean physics and climate

License

Transfer of copyrights occurs on the basis of a license agreement between the Author and Shirshov Institute of Oceanology, RAS

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