• Allan, R J., , and M. Haylock, 1993: Circulation features associated with the winter rainfall decrease in southwestern Australia. J. Climate, 6 , 13561367.

    • Search Google Scholar
    • Export Citation
  • Ansell, T J., , C. J. C. Reason, , I N. Smith, , and K. Keay, 2000: Evidence for decadal variability in southern Australian rainfall and relationships with regional pressure and sea surface temperature. Int. J. Climatol., 20 , 11131129.

    • Search Google Scholar
    • Export Citation
  • Bjerknes, J., 1969: Atmospheric teleconnections from the equatorial Pacific. Mon. Wea. Rev., 97 , 163172.

  • Cavazos, T., 1999: Large-scale circulation anomalies conducive to extreme precipitation events and derivation of daily rainfall in northeastern Mexico and southeastern Texas. J. Climate, 12 , 15061523.

    • Search Google Scholar
    • Export Citation
  • Cavazos, T., 2000: Using self-organizing maps to investigate extreme climate events: An application to wintertime precipitation in the Balkans. J. Climate, 13 , 17181732.

    • Search Google Scholar
    • Export Citation
  • Cook, K H., 2000: The South Indian convergence zone and interannual rainfall variability over southern Africa. J. Climate, 13 , 37893804.

    • Search Google Scholar
    • Export Citation
  • Cook, K H., 2001: A Southern Hemisphere wave response to ENSO with implications for southern Africa precipitation. J. Atmos. Sci., 58 , 21462162.

    • Search Google Scholar
    • Export Citation
  • D’Abreton, P C., , and J A. Lindesay, 1993: Water vapour transport over southern Africa during wet and dry early and late summer months. Int. J. Climatol., 13 , 151170.

    • Search Google Scholar
    • Export Citation
  • D'Abreton, P C., , and P D. Tyson, 1995: Divergent and non-divergent water vapour transport over southern Africa during wet and dry conditions. Meteor. Atmos. Phys., 55 , 4759.

    • Search Google Scholar
    • Export Citation
  • Dima, I M., , and J M. Wallace, 2003: On the seasonality of the Hadley cell. J. Atmos. Sci., 60 , 15221527.

  • Douville, H., , F. Chauvin, , and H. Broqua, 2001: Influence of soil moisture on the Asian and African monsoons. Part I: Mean monsoon and daily precipitation. J. Climate, 14 , 23812403.

    • Search Google Scholar
    • Export Citation
  • Eastin, M D., , and D G. Vincent, 1998: A 6-yr climatology of vertical mean and shear components of kinetic energy for the Australian–South Pacific jet stream. J. Climate, 11 , 283291.

    • Search Google Scholar
    • Export Citation
  • Gentilli, J., 1991: Homologous peri-oceanic west coast climates in the Southern Hemisphere. J. Roy. Soc. West. Aust., 74 , 1533.

  • Godfred-Spenning, C R., , and C. J. C. Reason, 2002: Interannual variability of lower-tropospheric moisture transport during the Australian monsoon. Int. J. Climatol., 22 , 509532.

    • Search Google Scholar
    • Export Citation
  • Hayes, M J., , M D. Svoboda, , D A. Wilhite, , and O V. Vanyarkho, 1999: Monitoring the 1006 drought using the Standardized Precipitation Index. Bull. Amer. Meteor. Soc., 80 , 429438.

    • Search Google Scholar
    • Export Citation
  • Hewitson, B C., , and R G. Crane, 2002: Self-organizing maps: Applications to synoptic climatology. Climate Res., 22 , 1326.

  • Holopainen, E O., 1970: An observational study of the energy balance of the stationary disturbances in the atmosphere. Quart. J. Roy. Meteor. Soc., 96 , 626644.

    • Search Google Scholar
    • Export Citation
  • Huang, H-J., , and D G. Vincent, 1985: Significance of the South Pacific convergence zone in energy conversions of the Southern Hemisphere during FGGE, 10–27 January 1979. Mon. Wea. Rev., 113 , 13591371.

    • Search Google Scholar
    • Export Citation
  • Jones, D A., , and I. Simmonds, 1993: A climatology of Southern Hemisphere extratropical cyclones. Climate Dyn., 9 , 131145.

  • Jury, M R., , H R. Valentine, , and J. R. E. Lutjeharms, 1993: Influence of the Agulhas Current on summer rainfall along the southeast coast of South Africa. J. Appl. Meteor., 32 , 12821287.

    • Search Google Scholar
    • Export Citation
  • Jury, M R., , B. Pathack, , C J. de W Rautenbach, , and J. van Heerden, 1996: Drought over South Africa and Indian Ocean SST: Statistical and GCM results. Global Atmos.–Ocean Syst., 4 , 4763.

    • Search Google Scholar
    • Export Citation
  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77 , 437471.

  • Kohonen, T., 1995: Self-Organizing Maps. Springer, 362 pp.

  • Lorenz, E N., 1955: Available potential energy and the maintenance of the general circulation. Tellus, 7 , 157167.

  • Mason, S J., 1995: Sea-surface temperature—South African rainfall associations, 1910–1989. Int. J. Climatol., 15 , 119135.

  • Mason, S J., , and P D. Tyson, 1992: The modulation of sea surface temperature and rainfall associations over southern Africa with solar activity and the quasi-biennial oscillation. J. Geophys. Res., 97 , 58475856.

    • Search Google Scholar
    • Export Citation
  • Mason, S J., , and M R. Jury, 1997: Climatic variability and change over southern Africa: A reflection on underlying processes. Prog. Phys. Geogr., 21 , 2350.

    • Search Google Scholar
    • Export Citation
  • Mo, K C., , and G H. White, 1985: Teleconnections in the Southern Hemisphere. Mon. Wea. Rev., 113 , 2237.

  • New, M., , M. Hulme, , and P. Jones, 2000: Representing twentieth-century space–time climate variability. Part II: Development of 1900–1998 monthly grids of terrestrial surface climate. J. Climate, 13 , 22172238.

    • Search Google Scholar
    • Export Citation
  • Newell, R E., , J W. Kidson, , D G. Vincent, , and G J. Boer, 1972: The General Circulation of the Tropical Atmosphere and Interactions with Extratropical Latitudes. Vol. 1. MIT Press, 258 pp.

    • Search Google Scholar
    • Export Citation
  • Oort, A H., 1964: On estimates of the atmospheric energy cycle. Mon. Wea. Rev., 92 , 483493.

  • Peixoto, J P., , and A. Oort, 1974: The annual distribution of atmospheric energy on a planetary scale. J. Geophys. Res., 79 , 21492159.

    • Search Google Scholar
    • Export Citation
  • Peterson, R G., , and W B. White, 1998: Slow oceanic teleconnections linking the Antarctic Circumpolar Wave with the tropical El Niño–Southern Oscillation. J. Geophys. Res., 103 , 2457324583.

    • Search Google Scholar
    • Export Citation
  • Reason, C. J. C., 1998: Warm and cold events in the southeast Atlantic/southwest Indian Ocean region and potential impacts on circulation and rainfall over southern Africa. Meteor. Atmos. Phys., 69 , 4965.

    • Search Google Scholar
    • Export Citation
  • Reason, C. J. C., 2001: Evidence for the influence of the Agulhas Current on regional atmospheric circulation patterns. J. Climate, 14 , 27692778.

    • Search Google Scholar
    • Export Citation
  • Reason, C. J. C., , and H M. Mulenga, 1999: Relationships between South African rainfall and SST anomalies in the south west Indian Ocean. Int. J. Climatol., 19 , 16511673.

    • Search Google Scholar
    • Export Citation
  • Reason, C. J. C., , R J. Allan, , J A. Lindesay, , and T J. Ansell, 2000: ENSO and climatic signals across the Indian Ocean basin in the global context: Part I, Interannual composite patterns. Int. J. Climatol., 20 , 12851327.

    • Search Google Scholar
    • Export Citation
  • Reason, C. J. C., , M. Rouault, , J L. Mélice, , and D. Jagadeesha, 2002: Interannual winter rainfall variability in SW South Africa and large scale ocean–atmosphere interactions. Meteor. Atmos. Phys., 80 , 1929.

    • Search Google Scholar
    • Export Citation
  • Rogers, J C., 1984: Association between the North Atlantic Oscillation and the Southern Oscillation in the Northern Hemisphere. Mon. Wea. Rev., 112 , 19992015.

    • Search Google Scholar
    • Export Citation
  • Ropelewski, C F., , and M S. Halpert, 1987: Global and regional scale precipitation patterns associated with the El Niño/Southern Oscillation. Mon. Wea. Rev., 115 , 16061626.

    • Search Google Scholar
    • Export Citation
  • Slingo, J M., , and H. Annamalai, 2000: 1997: The El Niño of the century and the response of the Indian summer monsoon. Mon. Wea. Rev., 128 , 17781797.

    • Search Google Scholar
    • Export Citation
  • Smith, I N., , P. McIntosh, , T J. Ansell, , C. J. C. Reason, , and K L. McInnes, 2000: South-west western Australian winter rainfall and its association with Indian Ocean climate variability. Int. J. Climatol., 20 , 19131930.

    • Search Google Scholar
    • Export Citation
  • Taljaard, J J., 1967: Development, distribution and movement of cyclones and anticyclones in the Southern Hemisphere during the IGY. J. Appl. Meteor., 6 , 973987.

    • Search Google Scholar
    • Export Citation
  • Tennant, W J., 2003: An assessment of intra-seasonal variability from 13-yr GCM simulations. Mon. Wea. Rev., 131 , 19751991.

  • Tennant, W J., 2004: Considerations when using pre-1979 NCEP/NCAR reanalyses in the Southern Hemisphere. Geophys. Res. Lett., 31 .L11112, doi:10.1029/2004GL019751.

    • Search Google Scholar
    • Export Citation
  • Tennant, W J., , and B C. Hewitson, 2002: Intra-seasonal rainfall characteristics and their importance to the seasonal prediction problem. Int. J. Climatol., 22 , 10331048.

    • Search Google Scholar
    • Export Citation
  • Todd, M., , and R. Washington, 1999: Circulation anomalies associated with tropical–temperate troughs in southern Africa and the south west Indian Ocean. Climate Dyn., 15 , 937951.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K E., 1991: Storm tracks in the Southern Hemisphere. J. Atmos. Sci., 48 , 21592178.

  • Trenberth, K E., , G W. Branstator, , D. Karoly, , A. Kumar, , N-C. Lau, , and C. Ropelewski, 1998: Progress during TOGA in understanding and modeling global teleconnections associated with tropical sea surface temperatures. J. Geophys. Res., 103 , 1429114324.

    • Search Google Scholar
    • Export Citation
  • Van den Heever, S C., , P C. D’Abreton, , and P D. Tyson, 1997: Numerical simulation of tropical–temperate troughs over southern Africa using the CSU RAMS model. S. Afr. J. Sci., 93 , 359365.

    • Search Google Scholar
    • Export Citation
  • Wiin-Nielsen, A., 1962: On transformation of kinetic energy between the vertical shear flow and the vertical mean flow in the atmosphere. Mon. Wea. Rev., 90 , 311322.

    • Search Google Scholar
    • Export Citation
  • Wright, W J., 1997: Tropical–extratropical cloudbands and Australian rainfall. Int. J. Climatol., 17 , 817829.

  • Yarnal, B., 1985: Extra-tropical teleconnections with El Niño–Southern Oscillation (ENSO) events. Prog. Phys. Geogr., 9 , 315352.

  • Yarnal, B., , and G. Kiladis, 1985: Tropical teleconnections associated with El Niño/Southern Oscillation (ENSO) events. Prog. Phys. Geogr., 9 , 524558.

    • Search Google Scholar
    • Export Citation
  • Zheng, X., , and E. A. B. Eltahir, 1998: The role of vegetation in the dynamics of West African monsoons. J. Climate, 11 , 20782096.

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Associations between the Global Energy Cycle and Regional Rainfall in South Africa and Southwest Australia

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  • 1 South African Weather Service, Pretoria, South Africa
  • | 2 Oceanography Department, University of Cape Town, Rondebosch, South Africa
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Abstract

Large-scale atmospheric processes in the Southern Hemisphere are examined on both seasonal and daily time scales in order to seek associations between these and regional rainfall variability in the summer rainfall areas of South Africa and the winter rainfall regions of South Africa and Western Australia. The basis of the analysis is atmospheric energetics of the vertical mean and shear flow. Self-organizing maps (SOMs) are then used to find archetypical states of the daily flow and to assess how the frequency characteristics of these states change between wet and dry years.

The results show clear associations between the frequency of circulation archetypes on a hemispheric scale and regional rainfall for both summer and winter rainfall areas. Substantial changes in archetype frequencies between wet and dry years are found with as much as a doubling or halving of the number of days in which certain archetypes occur within a season. The physical reasons for observed teleconnections are shown by way of the atmospheric energy cycle, providing a deeper understanding of climate variability that may benefit extended-range prediction.

Corresponding author address: Dr. Warren Tennant, South African Weather Service, Private Bag X097, Pretoria 0001, South Africa. Email: tennant@weathersa.co.za

Abstract

Large-scale atmospheric processes in the Southern Hemisphere are examined on both seasonal and daily time scales in order to seek associations between these and regional rainfall variability in the summer rainfall areas of South Africa and the winter rainfall regions of South Africa and Western Australia. The basis of the analysis is atmospheric energetics of the vertical mean and shear flow. Self-organizing maps (SOMs) are then used to find archetypical states of the daily flow and to assess how the frequency characteristics of these states change between wet and dry years.

The results show clear associations between the frequency of circulation archetypes on a hemispheric scale and regional rainfall for both summer and winter rainfall areas. Substantial changes in archetype frequencies between wet and dry years are found with as much as a doubling or halving of the number of days in which certain archetypes occur within a season. The physical reasons for observed teleconnections are shown by way of the atmospheric energy cycle, providing a deeper understanding of climate variability that may benefit extended-range prediction.

Corresponding author address: Dr. Warren Tennant, South African Weather Service, Private Bag X097, Pretoria 0001, South Africa. Email: tennant@weathersa.co.za

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