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Journal of Oceanography

, Volume 64, Issue 4, pp 551–560 | Cite as

Comparison of surface wind stress characteristics over the Tropical Atlantic (10°N–40°S) in fields derived from the UWM/COADS, NCEP/NCAR and QuikSCAT datasets

  • Vadlamudi Brahmananda Rao
  • Emanuel GiarollaEmail author
  • Clóvis Monteiro do Espírito Santo
  • Sergio Henrique Franchito
Short Contribution

Abstract

A comparison of monthly wind stress derived from winds of NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) reanalysis and UWM/COADS (The University of Wisconsin-Milwaukee/Comprehensive Ocean-Atmosphere Data Set) dataset (1950–1993), and of NCEP/NCAR reanalysis and satellite-based QuikSCAT dataset (2000–2006), is made over the South Atlantic (10°N–40°S). On a mean seasonal scale, the comparison shows that these three wind stress datasets have qualitatively similar patterns. Quantitatively, in general, from about the equator to 20°S in the mid-Atlantic the wind stress values are stronger in NCEP/NCAR data than those in UWM/COADS data. On the other hand, in the Intertropical Convergence Zone (ITCZ) area the wind stress values in NCEP/NCAR data are slightly weaker than those in UWM/COADS data. In the South Atlantic, between 20° S–40°S, the QuikSCAT dataset presents complex circulation structures which are not present in NCEP/NCAR and UWM/COADS data. The wind stress is used in a numerical ocean model to simulate ocean currents, which are compared to a drifting-buoy observed climatology. The modeled South Equatorial Current agrees better with observations between March–May and June–August. Between December–February, the South Equatorial Current from UWM/COADS and QuikSCAT experiments is stronger and more developed than that from NCEP/NCAR experiment. The Brazil Current, in turn, is better represented in the QuikSCAT experiment. Comparison of the annual migration of ITCZ at 20° and 30°W in UWM/COADS and NCEP/NCAR data sources show that the southernmost position of ITCZ at 30°W in February, March and April coincides with the rainy season in NE Brazil, while the northernmost position of ITCZ at 20°W in August coincides with the maximum rainfall of Northwest Africa.

Keywords

Wind stress ocean modeling Intertropical Convergence Zone UWM/COADS NCEP/NCAR reanalysis QuikSCAT dataset 

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References

  1. Bleck, R., C. Rooth, D. Hu and L. T. Smith (1992): Salinity-driven thermocline transients in a wind-and thermohaline-forced isopycnic coordinate model of the North Atlantic. J. Phys. Oceanogr., 22, 1486–1505.CrossRefGoogle Scholar
  2. Brunke, M. A., C. W. Fairall, X. Zeng, L. Eymard and J. A. Curry (2003): Which bulk aerodynamic algorithms are least problematic in computing ocean surface turbulent fluxes? J. Climate, 16, 619–635.CrossRefGoogle Scholar
  3. Carton, J. A. (1997): See-saw sea. Nature, 385, 487–488.CrossRefGoogle Scholar
  4. Carton, J. A., X. Cao, B. S. Giese and A. M. da Silva (1996): Decadal and interannual SST variability in the Tropical Atlantic Ocean. J. Phys. Oceanogr., 26, 1165–1175.CrossRefGoogle Scholar
  5. Chang, P., L. Ji and H. Li (1997): A decadal climate variation in the Tropical Atlantic Ocean from thermodynamic air-sea interactions. Nature, 385, 516–518.CrossRefGoogle Scholar
  6. da Silva, A. M., C. C. Young and S. Levitus (1994): Atlas of surface marine data 1994 Vol. 1: Algorithms and procedure. NOAA Atlas NESDIS 6.Google Scholar
  7. Gill, A. E. (1982): Atmosphere-Ocean Dynamics. Academic Press, New York, 662 pp.Google Scholar
  8. Hastenrath, S. and L. Heller (1977): Dynamics of climatic hazards in Northeast Brazil. Quart. J. Roy. Meteor. Soc., 103, 77–92.CrossRefGoogle Scholar
  9. Hellerman, S. and M. Rosenstein (1983): Normal monthly wind stress data over the world ocean with error estimates. J. Phys. Oceanogr., 13, 1093–1104.CrossRefGoogle Scholar
  10. Huang, B. and J. Shukla (1996): A comparison of two surface wind stress analyses over the Tropical Atlantic during 1980–1987. J. Climate, 9, 906–927.CrossRefGoogle Scholar
  11. Josey, S. A., E. C. Kent and P. K. Taylor (2002): Wind stress forcing of the ocean in the SOC climatology: comparisons with the NCEP-NCAR, ECMWF, UWM/COADS, and Hellerman and Rosenstein datasets. J. Phys. Oceanogr., 32, 1993–2019.CrossRefGoogle Scholar
  12. Kalnay, E. and Coauthors (1996): The NCEP/NCAR 40 year reanalysis project. Bull. Amer. Meteor. Soc., 77, 437–471.CrossRefGoogle Scholar
  13. Large, W. G. and S. Pond (1981): Open ocean momentum flux measurements in moderate to strong winds. J. Phys. Oceanogr., 11, 324–336.CrossRefGoogle Scholar
  14. Liu, W. T. (2002): Progress in scatterometer application. J. Oceanogr., 58, 121–136.CrossRefGoogle Scholar
  15. Lumpkin, R. and Z. Garraffo (2005): Evaluating the decomposition of Tropical Atlantic drifter observations. J. Atmos. Oceanic Technol. I, 22, 1403–1415.CrossRefGoogle Scholar
  16. Nicholson, S. E. and I. M. Palao (1993): A re-evaluation of rainfall variability in the Sahel. Part I. Characteristics of rainfall fluctuations. Int. J. Climatol., 13, 371–389.CrossRefGoogle Scholar
  17. Nobre, P. and J. Shukla (1996): Variations of sea surface temperature, wind stress, and rainfall over the Tropical Atlantic and South America. J. Climate, 9, 2464–2479.CrossRefGoogle Scholar
  18. Oberhuber, J. M. (1988): An atlas based on the COADS data set: the budgets of heat, buoyancy and turbulent kinetic energy at the surface of the global ocean. Tech. Rep. 15, Max-Planck-Institut für Meteorologie.Google Scholar
  19. Rao, V. B., S. R. Chapa and S. H. Franchito (1999): Decadal variation of atmosphere-ocean interaction in the Tropical Atlantic and its relationship to the Northeast Brazil rainfall. J. Meteor. Soc. Japan, 77, 63–75.CrossRefGoogle Scholar
  20. Servain, J. and S. Lukas (1990): Climatic atlas of the Tropical Atlantic wind stress and sea surface temperature 1985–1989. IFREMER, Brest, France. ISBN 2-905-434-28-7, 133 pp.Google Scholar
  21. Servain, J., M. Seva, S. Lukas and G. Rougier (1987): Climatic atlas of the Tropical Atlantic wind stress and sea surface temperature: 1980–1984. Ocean-Air Interact. 1, 109–182.Google Scholar
  22. Smith, S. R., D. M. Legler and K. V. Verzone (2001): Quantifying uncertainties in NCEP reanalyses using high-quality research vesses observations. J. Climate, 14, 4062–4072.CrossRefGoogle Scholar
  23. Taylor, P. K. (2000): Intercomparison and validation of ocean-atmosphere energy flux fields. Report of the Joint WCRP/SCOR Working Group on Air-Sea Fluxes, WCRP112 WMO/TD1036, 310 pp.Google Scholar
  24. Trenberth, K. E., W. G. Large and J. G. Olson (1990): The mean annual cycle in global ocean wind stress. J. Phys. Oceanogr., 20, 1742–1760.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Vadlamudi Brahmananda Rao
    • 1
  • Emanuel Giarolla
    • 1
    Email author
  • Clóvis Monteiro do Espírito Santo
    • 1
  • Sergio Henrique Franchito
    • 1
  1. 1.Centro de Previsão de Tempo e Estudos Climáticos, CPTECInstituto Nacional de Pesquisas Espaciais, INPE, CP 515São José dos Campos, SPBrazil

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