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Altimeter Data Analysis of the Antarctic Circumpolar Current

  • A. Simone
  • S. Zoffoli
  • D. Iudicone
  • R. Santoleri
  • S. Marullo
Conference paper

Abstract

The first two years of TOPEX/POSEIDON altimeter measurements of the Southern Ocean, between 30° S and 65° S were analyzed in order two study the mesoscale characteristics of the basin. Objective maps of sea level anomalies were computed for each cycle, showing synoptic view of the mesoscale activity of the study area. These maps underlined a population of mesoscale eddies, with a typical diameter of 100-200 Km in the sector 10° - 50° E and 30° _ 60° W, possibly shed from the meanders of the Antarctic Circumpolar Current. The rings seem to move southward confined to a rather narrow corridor (about 400Km). Sea level variability maps were computed to characterize the mesoscale activity in the study area. The highest values of more 25 cm are found between 10° - 60° E and near 50° W at a latitude of 40° - 50° S. A high variability area extends to at least 60° - 65° S. The TOPEX/POSEIDON cross-over data were used to resolve both magnitude and direction of residual geostrophic velocities. The time series are then used to determine surface eddy statistics in the Southern Ocean, hence the spatial distribution in the surface Reynolds stresses (u’2, v’2, u’v’). According with the information available so far, we found that the complex spatial distribution of surface eddy momentum flux is strongly influenced by bottom topography and the position of the mean current.

Keywords

Southern Ocean Altimeter Data Antarctic Circumpolar Current Mesoscale Eddy Drake Passage 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Tapley B.D, Ries JC, Davis GW, Eanes RJ, Schutz BE, Shum CK, Watkins MM, Marshall JA, Nerem RS, Putney BH, Klosko SM, Luthcke SB, Pavlis D, Williamson RG, Zelensky NP (1994) Precision orbit determination for TOPEX/POSEIDON. J Geophys Res 99 (C12): 24383–24404CrossRefGoogle Scholar
  2. 2.
    Nowlin WD Jr, Klinck JM(1986) The physics of the Antarctic Circumpolar Current. Rev Geophys 24: 469–491Google Scholar
  3. 3.
    Nowlin WD Jr, Clifford M (1982) The Kinematic and thermohaline zonation of the Antarctic Circumpolar Current at Drake Passage. J Mar Res 40S: 481–507Google Scholar
  4. 4.
    Munk WH, Palmen E (1951) Note on the dynamics of the Antarctic Circumpolar Current. Tellus 3: 53–55CrossRefGoogle Scholar
  5. 5.
    Hughes CW, Killworth PD (1995) Effects of bottom topography in the large-scale circulation of the Southern Ocean. JPO 25: 2485–2497CrossRefGoogle Scholar
  6. 6.
    Wells NC, de Cuevas BA (1995) Depth-integrated vorticity budget of the Southern Ocean from a general circulation model. JPO 25: 2569–2582CrossRefGoogle Scholar
  7. 7.
    McWilliams JC, Holand WR, Chow JS (1978) A description of numerical Antarctic Circumpolar Current, Dyn. Atmos Oceans 2: 213–291Google Scholar
  8. 8.
    Stevens DP, Ivchenko VD (1996) The zonal momentum balance in a realistic eddy resolving general circulation model of the Southern Ocean. Quart J Roy Meteor Soc, submittedGoogle Scholar
  9. 9.
    Ivchenko VO, Kelvin JR, Davin PS (1996) The dynamics of the ACC. JPO 26: 753–774CrossRefGoogle Scholar
  10. 10.
    Morrow R, Coleman R, Church J, Chelton D (1994) Surface eddy momentum flux and velocity variance in the southern ocean from Geosat altimetry. J Phys Oceanogr 24: 2050–2071CrossRefGoogle Scholar
  11. 11.
    Chelton DB, Schlax MG, Witter DL, Richman JC (1990) Geosat altimeter observation of the surface circulation of the Southern Ocean. J Geophys Res 95 (C10): 877–904CrossRefGoogle Scholar
  12. 12.
    Morrow R, Church J, Coleman R, Chelton D, White N (1992) Eddy momentum flux and its contribution to the Southern Ocean momentum balance. Nature 357: 482–484CrossRefGoogle Scholar
  13. 13.
    Johnson TJ, Stewart RH, Shum CK, Tapley BD (1992) Distribution of Reynolds stress carried by mesoscale variability in the Antartic Circumpolar Current, Geophys Res Lett 19: 1201–1204CrossRefGoogle Scholar
  14. 14.
    Gille ST (1994) Mean surface height of the Antarctic Circumpolar Current. J Geophys Res 99 (C9): 255–273CrossRefGoogle Scholar
  15. 15.
    Park Y, Gamberoni L (1995) Large-scale circulation and its variability in the south Indian Ocean from TOPEX/POSEIDON altimetry. J Geophys Res 100 (C12): 911–929CrossRefGoogle Scholar
  16. 16.
    AA.VV.,AVISO user handbook: merged TOPEX/POSEIDON products (1992) AVI-NT-02–101-CN, 2nd Ed, CNES, ToulouseGoogle Scholar
  17. 17.
    Fu LL, Christensen EJ, Yamarone CA, Lefebvre M, Menard Y, Dorrer M, Escudier P (1994) Topex/Poseidon mission overview. J Geophys Res 99(C12):24, 369–24, 381Google Scholar
  18. 18.
    Bretherton FP, Davis RE, Frandy CB (1976) A technique for objective analysis and design of oceanographic experiments applied to MODE-73. Deep sea Res 23: 559–582Google Scholar
  19. 19.
    Gouretsky VV, Danilov AL (1994) Characteristic of warm rings in the African sector of the Antarctic Circumpolar Current. Deep sea Res 40: 1131–1157CrossRefGoogle Scholar
  20. 20.
    Figueroa HA, Olson DB (1989) Lagrangian statistic in the South Atlantic as derived from SOS and FGGE drifters. J Marine Res 47: 525–546CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Italia, Milano 1999

Authors and Affiliations

  • A. Simone
    • 1
  • S. Zoffoli
    • 1
  • D. Iudicone
    • 1
  • R. Santoleri
    • 1
  • S. Marullo
    • 2
  1. 1.Istituto di Fisica dell’AtmosferaCNRRomeItaly
  2. 2.Casaccia S. Maria di GaleriaENEARomeItaly

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