Editorial Type:
Article
Article Type:
Research Article

The 1976/77 Austral Summer Climate Transition Effects on the Atmospheric Circulation and Climate in Southern South America

Eduardo A. Agosta Equipo Interdisciplinario para el Estudio de Procesos Atmosféricos en el Cambio Global, Pontificia Universidad Católica Argentina de Buenos Aires, and Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina

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Rosa H. Compagnucci Departamento de Ciencias de la Atmósfera y Los Océanos, Universidad de Buenos Aires, and Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina

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Print Publication:
01 Sep 2008
DOI:
https://doi.org/10.1175/2008JCLI2137.1
Page(s):
4365–4383
Restricted access

Abstract

Previous works suggest that more El Niño–like conditions can be expected over the South American (SA) climate and atmospheric circulation because of the similarity of the predominately warm conditions in the sea surface temperature (SST) over the central-equatorial Pacific after the 1976/77 summer with those of the SSTs during El Niño events. Here, the summer (October to March) low-level atmospheric circulation over southern SA is studied in order to determine the specific changes that can be related with the global climate transition 1976/77. The rotated principal component analysis is applied to the daily 850-hPa geopotential height fields from the NCEP–NCAR reanalysis I for the periods before and after 1976/77. The second and third principal patterns reveal changes both in the order of explained variances and in some of their spatial features. They can be associated with an expansion of the subtropical South Atlantic anticyclone over SA and lower midlatitude cyclone activity after the 1976/77 summer. The latter is partly associated with the actual tendency toward the positive phase of the southern annular mode. The main patterns can even explain some changes in the observed precipitation over subtropical central-west Argentina as well as for other subtropical regions. Different inhomogeneity tests applied to the atmospheric circulation climatology support the changes. Results suggest that the atmospheric circulation change could be somewhat unique (not observed in the twentieth century) and, thus, it could not be thoroughly ascribed to the El Niño–like variability.

Corresponding author address: Eduardo A. Agosta, PEPACG, UCA/CONICET, Freire 183, Buenos Aires C1426AVC, Argentina. Email: agosta@at.fcen.uba.ar

Abstract

Previous works suggest that more El Niño–like conditions can be expected over the South American (SA) climate and atmospheric circulation because of the similarity of the predominately warm conditions in the sea surface temperature (SST) over the central-equatorial Pacific after the 1976/77 summer with those of the SSTs during El Niño events. Here, the summer (October to March) low-level atmospheric circulation over southern SA is studied in order to determine the specific changes that can be related with the global climate transition 1976/77. The rotated principal component analysis is applied to the daily 850-hPa geopotential height fields from the NCEP–NCAR reanalysis I for the periods before and after 1976/77. The second and third principal patterns reveal changes both in the order of explained variances and in some of their spatial features. They can be associated with an expansion of the subtropical South Atlantic anticyclone over SA and lower midlatitude cyclone activity after the 1976/77 summer. The latter is partly associated with the actual tendency toward the positive phase of the southern annular mode. The main patterns can even explain some changes in the observed precipitation over subtropical central-west Argentina as well as for other subtropical regions. Different inhomogeneity tests applied to the atmospheric circulation climatology support the changes. Results suggest that the atmospheric circulation change could be somewhat unique (not observed in the twentieth century) and, thus, it could not be thoroughly ascribed to the El Niño–like variability.

Corresponding author address: Eduardo A. Agosta, PEPACG, UCA/CONICET, Freire 183, Buenos Aires C1426AVC, Argentina. Email: agosta@at.fcen.uba.ar

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  • Agosta, E. A., and R. H. Compagnucci, 2006: Atmospheric conditions during wet and dry summer extremes in central-west Argentina. Proc. Eighth Int. Conf. on Southern Hemisphere Meteorology and Oceanography, Foz do Iguaçu, Brazil, Amer. Meteor. Soc. and the Brazilian Institute for Space Research (INPE), 1439–1452.

  • Agosta, E. A., R. H. Compagnucci, and M. W. Vargas, 1999: Cambios en el régimen interannual de la precipitación en la región Centro-Oste de Argentina (Changes in the interannual precipitation regime over Central-West Argentina). Meteorologica, 24 , 63–84.

    • Search Google Scholar
    • Export Citation

  • Allan, R. J., and M. R. Haylock, 1993: Circulation features associated with the winter rainfall decrease in southwestern Australia. J. Climate, 6 , 1356–1367.

    • Search Google Scholar
    • Export Citation

  • Barros, V. R., and L. M. Scasso, 1994: Surface pressure and temperature anomalies in Argentina in connection with the Southern Oscillation. Atmósfera, 94 , 1159–1171.

    • Search Google Scholar
    • Export Citation

  • Barros, V. R., M. Castañeda, and M. Doyle, 1996: Recent precipitation trends in southern South America to the east of the Andes: An indication of a mode of climatic variability. Greenhouse Gas Emission under Developing Countries Point of View, L. P. Rosa and M. A. Santos, Eds., COPPE, 41–67.

    • Search Google Scholar
    • Export Citation

  • Barros, V. R., M. E. Casteñeda, and M. Doyle, 2000a: Recent precipitation trends in southern South America east of the Andes: An indication of climatic variability. Southern Hemisphere Paleo and Neo-climates, P. P. Smolka and W. Volkheimer, Eds., Springer-Verlag, 187–206.

    • Search Google Scholar
    • Export Citation

  • Barros, V. R., M. Gonzalez, B. Liebmann, and I. Camilloni, 2000b: Influence of the South Atlantic Convergence Zone and South Atlantic sea surface temperature on interannual summer rainfall variability in southeastern South America. Theor. Appl. Meteor., 67 , 123–133.

    • Search Google Scholar
    • Export Citation

  • Bengtsson, L., S. Hagemann, and K. I. Hodges, 2004: Can climate trends be calculated from reanalysis data? J. Geophys. Res., 109 .D11111, doi:10.1029/2004JD004536.

    • Search Google Scholar
    • Export Citation

  • Boer, G. J., K. Hamilton, and W. Zhu, 2005: Climate sensitivity and climate change under strong forcing. Climate Dyn., 24 , 685–700.

  • Boulanger, J. P., J. Leloup, O. Penalba, M. Rusticucci, F. Lafon, and M. Vargas, 2005: Observed precipitation in the Paraná-Plata hydrological basin: Long term trends, extreme conditions and ENSO teleconnections. Climate Dyn., 24 , 393–413.

    • Search Google Scholar
    • Export Citation

  • Camilloni, I., 1999: Temporal variability of the Buenos Aires’ urban heat island intensity. Proc. Int. Conf. on Urban Climatology ICUC’99, Sydney, Australia, International Society of Biometeorology, World Meteorological Organisation, and the Australian Bureau of Meteorology.

  • Carril, A. F., M. E. Doyle, V. R. Barros, and M. N. Núñez, 1997: Impacts of climate change on the oases of the Argentinean cordillera. Climate Res., 9 , 121–129.

    • Search Google Scholar
    • Export Citation

  • Carvalho, L. M. V., C. Jones, and B. Liebmann, 2002: Extreme precipitation events in southeastern South America and large-scale convective patterns in the South Atlantic convergence zone. J. Climate, 15 , 2377–2394.

    • Search Google Scholar
    • Export Citation

  • Carvalho, L. M. V., C. Jones, and B. Liebmann, 2004: The South Atlantic Convergence Zone: Intensity, form, persistence, and relationships with intraseasonal to interannual activity and extreme rainfall. J. Climate, 17 , 88–108.

    • Search Google Scholar
    • Export Citation

  • Chen, T. C., J. H. Yoon, K. J. St Croix, and E. S. Takle, 2001: Suppressing impacts of the Amazonian deforestation by the global circulation change. Bull. Amer. Meteor. Soc., 82 , 2209–2216.

    • Search Google Scholar
    • Export Citation

  • Chen, T. C., E. S. Takle, J. H. Yoon, K. J. St. Crox, and P. Hsieh, 2003: Impacts on tropical South American rainfall due to changes in global circulation. Proc. Seventh Int. Conf. on Southern Hemisphere Meteorology and Oceanography, Wellington, New Zealand, Amer. Meteor. Soc., 92–93.

  • Compagnucci, R. H., and M. Richman, 2008: Can principal component analysis provide atmospheric circulation or teleconnection patterns? Int. J. Climatol., 28 , 703–726. doi:10.1002/joc.1574.

    • Search Google Scholar
    • Export Citation

  • Compagnucci, R. H., E. A. Agosta, and M. W. Vargas, 2002: Climatic change and quasi-oscillations in central-west Argentina summer precipitation: Main features and coherent behaviour with southern African region. Climate Dyn., 18 , 421–435.

    • Search Google Scholar
    • Export Citation

  • Craddock, J. M., and C. R. Flood, 1969: Eigenvectors for representing the 500 mb geopotential surface over the Northern Hemisphere. Quart. J. Roy. Meteor. Soc., 95 , 576–593.

    • Search Google Scholar
    • Export Citation

  • Depaiva, E. M. C. D., and R. T. Clarke, 1995: Time trends in rainfall records in Amazonia. Bull. Amer. Meteor. Soc., 76 , 2203–2209.

  • Dettinger, M. D., D. S. Battisti, R. D. Garreaud, G. J. McCabe, and C. M. Bitz, 2001: Interhemispheric effects of interannual and decadal ENSO-like climate variations on the Americas. Interhemispheric Climate Linkages: Present and Past Climates in the Americas and their Societal Effects, V. Markgraf, Ed., Academic Press, 1–16.

    • Search Google Scholar
    • Export Citation

  • Ebbesmeyer, C. C., D. R. Cayan, D. R. McLain, F. H. Nichols, D. H. Peterson, and T. Redmond, 1991: 1976 Step in the Pacific Climate: Forty environmental changes between 1968–1975 and 1977–1984. California Department of Water Resources, Interagency Ecological Studies Program Tech. Rep. 26, 115–126.

  • Farmer, S. A., 1971: An investigation into the results of principal component analysis of data derived from random numbers. Statistician, 20 , 63–72.

    • Search Google Scholar
    • Export Citation

  • Garreaud, R. D., and D. S. Battisti, 1999: Interannual ENSO and interdecadal ENSO-like variability in the Southern Hemisphere. J. Climate, 12 , 2113–2123.

    • Search Google Scholar
    • Export Citation

  • Gong, D., and S. Wang, 1999: Definition of Antarctic Oscillation Index. Geophys. Res. Lett., 26 , 459–462.

  • Gu, D. F., and S. G. H. Philander, 1997: Interdecadal climate fluctuations that depend on exchanges between the tropics and extratropics. Science, 275 , 805–807.

    • Search Google Scholar
    • Export Citation

  • Hastenrath, S., and L. Greischar, 1993: Further work on the prediction of northeast Brazil rainfall anomalies. J. Climate, 6 , 743–758.

    • Search Google Scholar
    • Export Citation

  • Haylock, M. R., and Coauthors, 2006: Trends in total and extreme South American rainfall in 1960–2000 and links with sea surface temperature. J. Climate, 19 , 1490–1512.

    • Search Google Scholar
    • Export Citation

  • Holton, J., 1992: An Introduction to Dynamic Meteorology. 3rd ed. Academic Press, 511 pp.

  • Houghton, J. T., Y. Ding, D. J. Griggs, M. Noguer, P. J. van der Linden, X. Dai, K. Maskell, and C. A. Johnson, 2001: Climate Change 2001: The Scientific Basis. Cambridge University Press, 881 pp.

    • Search Google Scholar
    • Export Citation

  • Huang, H-P., R. Seager, and Y. Kushnir, 2005: The 1976/77 transition in precipitation over the Americas and the influence of tropical sea surface temperature. Climate Dyn., 24 , 721–740.

    • Search Google Scholar
    • Export Citation

  • Hurrell, J. W., and H. van Loon, 1994: A modulation of the atmospheric annual cycle in the Southern Hemisphere. Tellus, 46A , 325–338.

  • Kayano, M. T., and R. V. Andreoli, 2007: Relations of South American summer rainfall interannual variations with the Pacific Decadal Oscillation. Int. J. Climatol., 27 , 531–540.

    • Search Google Scholar
    • Export Citation

  • Key, J. R., and A. C. K. Chang, 1999: Multidecadal global and regional trends in 1000 mb and 500 mb cyclone frequencies. Geophys. Res. Lett., 26 , 2053–2056.

    • Search Google Scholar
    • Export Citation

  • Kidson, J. W., 1999: Principal modes of Southern Hemisphere low frequency variability obtained from NCEP–NCAR reanalyses. J. Climate, 12 , 2808–2830.

    • Search Google Scholar
    • Export Citation

  • Kistler, R., and Coauthors, 2001: The NCEP–NCAR 50-Year Reanalysis: Monthly means CD-ROM and documentation. Bull. Amer. Meteor. Soc., 82 , 247–267.

    • Search Google Scholar
    • Export Citation

  • Lenters, J. D., and K. H. Cook, 1995: Simulation and diagnosis of the regional summertime precipitation climatology of South America. J. Climate, 8 , 2988–3005.

    • Search Google Scholar
    • Export Citation

  • Lenters, J. D., and K. H. Cook, 1999: Summertime precipitation variability over South America: Role of the large-scale circulation. Mon. Wea. Rev., 127 , 409–431.

    • Search Google Scholar
    • Export Citation

  • Liebmann, B., and Coauthors, 2004: An observed trend in central South American precipitation. J. Climate, 17 , 4357–4367.

  • Limpasuvan, V., and D. L. Hartmann, 1999: Eddies and the annular modes of climate variability. Geophys. Res. Lett., 26 , 3133–3136.

  • Mantua, N. J., and S. R. Hare, 2002: The Pacific Decadal Oscillation. J. Oceanogr., 58 , 35–44.

  • Mantua, N. J., S. R. Hare, Y. Zhang, J. M. Wallace, and R. C. Francis, 1997: A Pacific interdecadal climate oscillation with impacts on salmon production. Bull. Amer. Meteor. Soc., 78 , 1069–1079.

    • Search Google Scholar
    • Export Citation

  • Marengo, J. A., 2004: Interdecadal variability and trends of rainfall across the Amazon basin. Theor. Appl. Climatol., 78 , 79–96.

  • Marshall, G. J., 2003: Trends in the southern annular mode from observations and reanalyses. J. Climate, 16 , 4134–4143.

  • McPhaden, M. J., and D. Zhang, 2002: Slowdown of the meridional overturning circulation in the upper Pacific Ocean. Nature, 415 , 603–608.

    • Search Google Scholar
    • Export Citation

  • Minetti, J. L., and W. M. Vargas, 1998: Trends and jumps in the annual precipitation in South America, south of 15°S. Atmósfera, 11 , 205–223.

    • Search Google Scholar
    • Export Citation

  • Minetti, J. L., W. M. Vargas, A. G. Poblete, L. R. Acuna, and G. Casagrande, 2003: Non-linear trends and low frequency oscillations in annual precipitation over Argentina and Chile, 1931–1999. Atmósfera, 16 , 119–135.

    • Search Google Scholar
    • Export Citation

  • Moser, B. K., and G. R. Stevens, 1992: Homogeneity of variance in the two-sample means test. Amer. Stat., 46 , 19–21.

  • Namias, J., 1978: Multiple causes of the North American abnormal winter 1976–1977. Mon. Wea. Rev., 106 , 279–295.

  • Nogués-Paegle, J., and Coauthors, 2002: Progress in pan American CLIVAR research: Understanding the South American Monsoon. Meteorologica, 27 , 1–30.

    • Search Google Scholar
    • Export Citation

  • North, G. R., T. L. Bell, R. F. Cahalan, and F. J. Moeng, 1982: Sampling errors in the estimation of empirical orthogonal functions. Mon. Wea. Rev., 110 , 699–706.

    • Search Google Scholar
    • Export Citation

  • Pezza, A. B., and T. Ambrizzi, 2003: Variability of Southern Hemisphere cyclone and anticyclone behavior: Further analysis. J. Climate, 16 , 1075–1083.

    • Search Google Scholar
    • Export Citation

  • Piovano, E. L., D. Ariztegui, S. M. Bernasconi, and J. A. McKenzie, 2004: Stable isotopic record of hydrological changes in subtropical Laguna Mar Chiquita (Argentina) over last 230 years. Holocene, 14 , 525–535.

    • Search Google Scholar
    • Export Citation

  • Preisendorfer, R. W., 1988: Principal Component Analysis in Meteorology and Oceanography. Elsevier, 425 pp.

  • Richman, M. B., 1986: Rotation of principal components. Int. J. Climatol., 6 , 293–335.

  • Robertson, A., and C. Mechoso, 1998: Interannual and decadal cycles in river flows of Southeastern South America. J. Climate, 11 , 2570–2581.

    • Search Google Scholar
    • Export Citation

  • Rusticucci, M., and O. Penalba, 2003: Interdecadal changes in the precipitation seasonal cycle over southern South America and their relationship with surface temperature. Climate Res., 16 , 1–15.

    • Search Google Scholar
    • Export Citation

  • Saulo, A. C., M. Nicolini, and S. C. Chou, 2000: Model characterization of South American low-level flow during the 1997–1998 spring–summer season. Climate Dyn., 16 , 867–881.

    • Search Google Scholar
    • Export Citation

  • Seager, R., N. Harnik, W. A. Robinson, Y. Kushnir, M. Ting, H. P. Huang, and J. Velez, 2005: Mechanisms of ENSO-forcing of hemispherically symmetric precipitation variability. Quart. J. Roy. Meteor. Soc., 131 , 1501–1527.

    • Search Google Scholar
    • Export Citation

  • Seluchi, M. E., A. C. Saulo, M. Nicolini, and P. Satyamurty, 2003: The Northwestern Argentinean Low: A study of two typical events. Mon. Wea. Rev., 131 , 2361–2378.

    • Search Google Scholar
    • Export Citation

  • Simmonds, I., and K. Keay, 2000: Variability of Southern Hemisphere extratropical cyclone behavior, 1958–97. J. Climate, 13 , 550–561.

    • Search Google Scholar
    • Export Citation

  • Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor, and H. L. Miller, Eds. 2007: Climate Change 2007: The Physical Science Basis. Cambridge University Press, 996 pp.

  • Thompson, D. W. J., and J. M. Wallace, 2000: Annular modes on the extratropical circulation. Part I: Month-to-month variability. J. Climate, 13 , 1000–1016.

    • Search Google Scholar
    • Export Citation

  • Thompson, D. W. J., and S. Solomon, 2002: Interpretation of recent Southern Hemisphere climate change. Science, 296 , 895–899.

  • Trenberth, K. E., 1990: Recent observed interdecadal climate changes in the Northern Hemisphere. Bull. Amer. Meteor. Soc., 71 , 988–993.

    • Search Google Scholar
    • Export Citation

  • Trenberth, K. E., 1995: Atmospheric circulation climate changes. Climatic Change, 31 , 427–453.

  • Trenberth, K. E., and J. W. Hurrell, 1994: Decadal atmosphere–ocean variations in the Pacific. Climate Dyn., 9 , 303–319.

  • van Loon, H., J. W. Kidson, and A. B. Mullan, 1993: Decadal variation of the annual cycle in the Australian dataset. J. Climate, 6 , 1227–1231.

    • Search Google Scholar
    • Export Citation

  • Vera, C., 2003: Interannual and interdecadal variability of atmospheric synoptic-scale activity in the Southern Hemisphere. J. Geophys. Res., 108 .8077, doi:10.1029/2000JC000406.

    • Search Google Scholar
    • Export Citation

  • Vera, C., and Coauthors, 2006: Toward a unified view of the American monsoon systems. J. Climate, 19 , 4997–5000.

  • Waylen, P., R. Compagnucci, and R. M. Caffera, 2000: Interannual and interdecadal variability in streamflow from the Argentine Andes. Phys. Geogr., 21 , 452–465.

    • Search Google Scholar
    • Export Citation

  • Yamamoto, R., Y. Iwashima, and T. Sanga, 1986: An analysis of climatic jump. J. Meteor. Soc. Japan, 64 , 273–280.

  • Zhang, Y., J. M. Wallace, and D. Battisti, 1997: ENSO-like interdecadal variability: 1900–93. J. Climate, 10 , 1004–1020.

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