Intercomparison of Heat Fluxes in the South Atlantic. Part I: The Seasonal Cycle

Ilana Wainer Department of Physical Oceanography, University of São Paulo, São Paulo, Brazil

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Andrea Taschetto Department of Physical Oceanography, University of São Paulo, São Paulo, Brazil

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Jacyra Soares Department of Atmospheric Sciences, University of São Paulo, São Paulo, Brazil

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Amauri Pereira de Oliveira Department of Atmospheric Sciences, University of São Paulo, São Paulo, Brazil

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Bette Otto-Bliesner National Center for Atmospheric Research, Boulder, Colorado

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Esther Brady National Center for Atmospheric Research, Boulder, Colorado

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Abstract

Intercomparison of the seasonal cycle for the fluxes of sensible and latent heat for four observation-based products [DaSilva, NCEP, Esbensen–Kushnir (EK), and the Southampton Oceanography Centre (SOC)] and the results for the NCAR Community Climate System Model (CCSM) are examined in order to gain an improved understanding of the South Atlantic characteristic spatial patterns. Their seasonal structure associated with ocean dynamics, evolution, and the net heat flux patterns are also discussed.

The key regions of the Brazil–Malvinas confluence, Agulhas retroflection, and Benguela upwelling region off Africa were chosen for a closer examination of the fluxes. All climatologies show very different behavior. The SOC product presents sudden changes in the seasonal cycle evolution, departing from the annual or semiannual observed pattern of EK and NCEP. Compared to the other climatologies, EK shows equivalent temporal behavior but different magnitudes because this climatology covers a period where much less data was available.

It was found that the eastern Atlantic shows more differences among the climatologies than the Brazil–Malvinas confluence region in the west. It is also in the eastern Atlantic that the difference between NCAR CCSM results and observations are bigger, probably due to a bias in cloud simulation, which affects the air–sea interaction dynamics. In the Brazil–Malvinas confluence region differences between the NCAR CCSM and the observed datasets are comparable to the difference between the observations themselves.

Corresponding author address: Dr. Ilana Wainer, Department of Physical Oceanography, University of São Paulo, Praca do Oceanografico 191, São Paulo, SP 05508-900 Brazil. Email: wainer@usp.br

Abstract

Intercomparison of the seasonal cycle for the fluxes of sensible and latent heat for four observation-based products [DaSilva, NCEP, Esbensen–Kushnir (EK), and the Southampton Oceanography Centre (SOC)] and the results for the NCAR Community Climate System Model (CCSM) are examined in order to gain an improved understanding of the South Atlantic characteristic spatial patterns. Their seasonal structure associated with ocean dynamics, evolution, and the net heat flux patterns are also discussed.

The key regions of the Brazil–Malvinas confluence, Agulhas retroflection, and Benguela upwelling region off Africa were chosen for a closer examination of the fluxes. All climatologies show very different behavior. The SOC product presents sudden changes in the seasonal cycle evolution, departing from the annual or semiannual observed pattern of EK and NCEP. Compared to the other climatologies, EK shows equivalent temporal behavior but different magnitudes because this climatology covers a period where much less data was available.

It was found that the eastern Atlantic shows more differences among the climatologies than the Brazil–Malvinas confluence region in the west. It is also in the eastern Atlantic that the difference between NCAR CCSM results and observations are bigger, probably due to a bias in cloud simulation, which affects the air–sea interaction dynamics. In the Brazil–Malvinas confluence region differences between the NCAR CCSM and the observed datasets are comparable to the difference between the observations themselves.

Corresponding author address: Dr. Ilana Wainer, Department of Physical Oceanography, University of São Paulo, Praca do Oceanografico 191, São Paulo, SP 05508-900 Brazil. Email: wainer@usp.br

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  • Bèranger, B. B., K. Viau, E. Garnier, J. Molines, and L. Siefridt, 1999: An atlas of climatic estimates of air-sea fluxes. Equipe de Modèlisation des Ecoulements Ocèaniques de Moyenne et Grand Echelle, Tech. Report, LEGI, Grenoble, France, 82 pp.

    • Search Google Scholar
    • Export Citation
  • Berliand, M. E., and T. G. Berliand, 1952: Determining the net long-wave radiation of the earth with consideration of the effect of cloudiness (in Russian). Tech. Rep. 1, Izvestiya Akademii Nauk SSSR, Seriya Geofizicheskaya.

    • Search Google Scholar
    • Export Citation
  • Boville, B., and P. R. Gent, 1998: The NCAR Climate System Model, version one. J. Climate, 11 , 11151130.

  • Boville, B., and J. Jurrel, 1998: A comparison of the atmospheric circulations simulated by the CCM3 and CSM1. J. Climate, 11 , 13271341.

    • Search Google Scholar
    • Export Citation
  • Budyko, M. I., 1963: Atlas of Heat Balance of the Earth. Akad. Nauk SSSR, Prezidum. Mezhduvedomstvennyi Geofiz. Komitet, 69 pp.

  • Bunker, A. F., 1988: Surface energy fluxes of the South Atlantic Ocean. Mon. Wea. Rev., 116 , 809823.

  • Campos, E., and Coauthors. 1999: The South Atlantic and climate. Proc. OCEANOBS'99: The Ocean Observing System for Climate, Vol. 1, Saint Raphael, France, Cent. Nat. Etudes Spatiales.

    • Search Google Scholar
    • Export Citation
  • Chelton, D., M. Schlax, D. Witter, and J. Richman, 1990: Geosat altimeter observations of the surface circulation of the southern oceans. J. Geophys. Res., 95 , 1787717903.

    • Search Google Scholar
    • Export Citation
  • Cheney, R., J. Marsh, and B. D. Beckley, 1983: Global mesoscale variability from collinear tracks of seasat altimetry data. J. Geophys. Res., 88 , 43434351.

    • Search Google Scholar
    • Export Citation
  • Clark, N. E., L. Eber, R. M. Laurs, J. A. Renner, and J. F. T. Saur, 1974: Heat exchange between ocean and atmosphere in the eastern North Pacific for 1966–71. NOAA Tech. Rep. NMFS SSRF-682, U.S. Dept. of Commerce, Washington, DC, 108 pp.

    • Search Google Scholar
    • Export Citation
  • Danabasoglu, G., 1998: On the wind-driven circulation of the uncoupled and coupled NCAR climate system ocean model. J. Climate, 11 , 14421454.

    • Search Google Scholar
    • Export Citation
  • Da Silva, A., A. Young, and S. Levitus, 1994: Algorithms and Procedures. Vol. 1, Atlas of Surface Marine Data 1994, NOAA Atlas NESDIS 6.

    • Search Google Scholar
    • Export Citation
  • Diaz, A. F., C. D. Studzinski, and C. R. Mechoso, 1998: Relationships between precipitation anomalies in Uruguay and southern Brazil and sea surface temperature in the Pacific and Atlantic Oceans. J. Climate, 11 , 251271.

    • Search Google Scholar
    • Export Citation
  • Esbensen, S., and Y. Kushnir, 1981: The heat budget of the global ocean: An atlas based on estimates from surface marine observations. Oregon State University, Tech. Rep. 29, 27 pp. plus figures.

    • Search Google Scholar
    • Export Citation
  • Gordon, A., 1988: Brazil–Malvinas confluence. Deep-Sea Res., 36A , 359384.

  • Josey, S. A., E. C. Kent, and P. Taylor, 1999: New insights into the ocean heat budget closure problem from analysis of the SOC air–sea flux climatology. J. Climate, 12 , 28562880.

    • Search Google Scholar
    • Export Citation
  • Kalnay, E., K. C. Mo, and J. Paegle, 1986: Large amplitude, short-scale stationary Rossby waves in the Southern Hemisphere: Observations and mechanistic experiments to determine their origin. J. Atmos. Sci., 43 , 252275.

    • Search Google Scholar
    • Export Citation
  • Large, W. G., and S. Pond, 1982: Sensible and latent heat flux measurements over the ocean. J. Phys. Oceanogr., 12 , 464482.

  • Lindau, R., 1995: A new Beaufort equivalent scale. Proc. Int. COADS Winds Workshop, Kiel, Germany, Institut fur Meereskunde Kiel and NOAA, 232–252.

    • Search Google Scholar
    • Export Citation
  • Liu, W. T., K. B. Katsaros, and J. A.. Businger, 1979: Bulk parameterization of air–sea exchange of heat and water vapor including molecular constraints at the interface. J. Atmos. Sci., 36 , 17221735.

    • Search Google Scholar
    • Export Citation
  • Lutjeharms, J., and R. van Ballegooyen, 1988: The retroflection of the Agulhas Current. J. Phys. Oceanogr., 18 , 15701583.

  • Norris, J. R., and C. P. Weaver, 2001: Improved techniques for evaluating GCM cloudiness applied to the NCAR CCM3. J. Climate, 14 , 25402550.

    • Search Google Scholar
    • Export Citation
  • Olson, D., and R. Evans, 1986: Rings of the Agulhas Current. Deep-Sea Res., 33A , 2742.

  • Olson, D., G. P. Podesta, R. H. Evans, and O. B. Brown, 1988: Temporal variations in the separation of brazil and Malvinas. Deep-Sea Res., 35A , 19711990.

    • Search Google Scholar
    • Export Citation
  • Reed, R. K., 1977: On estimating insolation over the ocean. J. Phys. Oceanogr., 7 , 482485.

  • Reynolds, R. W., and T. M. Smith, 1994: Improved global sea surface temperature analyses using optimum interpolation. J. Climate, 7 , 929948.

    • Search Google Scholar
    • Export Citation
  • Rosati, A., and K. Miyakoda, 1988: A general circulation model for upper ocean simulation. J. Phys. Oceanogr., 18 , 16011626.

  • Shea, D. J., K. E. Trenberth, and R. W. Reynolds, 1990: A global monthly sea surface temperature climatology. NCAR Tech. Note NCAR/TN-345, 167 pp.

    • Search Google Scholar
    • Export Citation
  • Smith, S. R., 1988: Coefficients for sea surface wind stress, heat flux, and wind profiles as a function of wind speed and temperature. J. Geophys. Res., 93 , 1546715472.

    • Search Google Scholar
    • Export Citation
  • Taylor, P. K., 2000: Intercomparison and validation of ocean–atmosphere energy flux fields. WCRP/SCOR Working Group on Air–Sea Fluxes, Final Rep. WCRP-112, WMO/TD-1036, 305 pp.

    • Search Google Scholar
    • Export Citation
  • Wainer, I., P. R. Gent, and G. Goni, 2000: The annual cycle of the Brazil-Malvinas confluence region in the NCAR Climate System Model. J. Geophys. Res., 105 , 2617626178.

    • Search Google Scholar
    • Export Citation
  • WMO, 1970: The Beaufort scale of wind force (technical and operational aspects). WMO Rep. 3, World Meteorological Organization Reports on Marine Affairs, 22 pp.

    • Search Google Scholar
    • Export Citation
  • Zavialov, P., I. Wainer, and J. Absy, 1999: Interdecadal, interannual and seasonal variability off southern Brazil and Uruguay as revealed from historical data since 1854. J. Geophys. Res., 104 , 2102121032.

    • Search Google Scholar
    • Export Citation
  • Zeng, X., M. Zhao, and R. Dickinson, 1998: Intercomparison of bulk aerodynamic algorithms for the computation of sea surface fluxes using the TOGA COARE and TAO data. J. Climate, 11 , 26282644.

    • Search Google Scholar
    • Export Citation
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