Summary
Preliminary climatological statistics of extreme weather events over the southern Africa region are established through analysis of daily weather maps of the South African Weather Bureau for a twenty year peiod, 1973–1992. Influences of global warming and inter-annual variability imposed by El Nino events, amongst others, are sought. Notable trends include a decrease in the frequency of station days with rainfall > 70 mm and an increase in station days with temperature > 38°C. Correlations offer some insights to extreme climate associations. Lows over the land in the west and over the sea to the east display consistent interannual variability, despite opposing rainfall regimes. Agreement in extreme temperature statistics in all regions suggest that drought is widespread over southern Africa. Rainfall in the north is negatively related to lows over the sea to the south. A potential mechanism underlying the inverse relationship between midlatitude and sub-tropical storminess is the development of a vorticity dipole associated with the westerly jet stream. This is investigated in an El Nino-influenced case study.
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Harangozo, A., Harrison, M. S. J., 1983: On the use of synoptic data in indicating the presence of cloud bands over southern Africa.South African J. Sci. 70, 413–414.
Joubert, A., 1994: Simulations of southern African climatic change by early-generation general circulation models.Water SA 20, 315–322.
Jury, M. R., Reason, C. J., 1989: Extreme subsidence in the Agulhas-Benguela air mass transition.Bound. Layer Meteor. 46, 35–51.
Jury, M. R., 1992: A climatic dipole governing the interannual variability of convection over the SW Indian Ocean and SE Africa region.Trends Geophys. Res., India, 165–172.
Jury, M. R., Lutjeharms, J. R. E., 1993: The structure and possible forcing mechanisms of the 1991–1992 drought in Southern Africa.S. Afr. Tyd. Nat. Tegn. 12, 8–16.
Jury, M. R., Pathack, B., Wang, B., Powell, M., Raholijao, N., 1993: A destructive tropical cyclone season in the SW Indian Ocean: Jauary–February 1984.South African Geogr. J. 75, 53–59.
Jury, M. R., Lyons, S. W., 1994: Contrasting synoptic weather events over southern Africa in the dry summer of 1983.South African Geogr. J. 76, 6–10.
Lambert, S. J., 1993: Southern hemisphere cyclone climatology and the Greenhouse effect. Proc. 4th Conf. S. Hem. Met. Ocean., Tasmania, Amer. Met. Soc. Boston, pp. 320–321.
Lutjeharms, J. R. E., Valentine, H. R., 1984: Southern ocean thermal fronts south of Africa.Deep Sea Res. 31/12, 1461–1475.
Lutjeharms, J. R. E., Mey, R. D., Hunter, I. T., 1986: Cloud lines over the Agulhas Current.South African J. Sci. 82/11, 635–640.
Makarau, A., 1995: Intra-seasonal oscillatory modes of the southern Africa summer circulation, PhD Thesis, Oceanogr. Dept., Univ. Cape Town.
Majodina, M., Jury, M. R., 1993: A climatological summary of extreme weather affecting southern Africa and surrounding oceans. Oceanogr., Dept. Univ. Cape Town, Tech. Rep., 47 pp.
Mey, R. D., Walker, N. D., Jury, M. R., 1990: Surface heat fluxes and marine boundary layer modification in the Agulhas retroflection region.J. Geophys. Res. 95/C9, 15997–16015.
Parker, B. A., Pathack, B., Jury, M. R., 1992: Atlas of southern African climate variability. Oceanogr. Dept., Univ. Cape Town, Tech. Rep., 158 pp.
Taljaard, J. J., 1967: Development, distribution and movement of cyclones and anticyclones in the southern hemisphere during the IGY.J. Appl. Meteor. 6, 973–987.
Taljaard, J. J., 1972: Synoptic meteorology of the southern hemisphere. In: Newton, C. W. (ed.),Meteorology of the Southern Hemisphere. Meteorological Monographs,13/35, 139–213.
Taljaard, J. J., 1981: The anomalous climate and weather systems of January to March 1974.South African Weather Bureau, Tech. Rep., 9, 92 pp.
Taljaard, J. J., 1982: Cut-off lows and heavy rain over South Africa.South African Weather Bureau Newsletter 403, 155–156.
Taljaard, J. J., 1985: Cut-off lows in the South Africa region, South African Weather Bureau, Pretoria, Tech. Rep. 14, 153 pp.
Taljaard, J. J., 1987: The anomalous climate and weather systems over South Africa during summer 1975–1976, South African Weather Bureau, Pretoria, Tech. Paper 16, 80 pp.
Taljaard, J. J., 1989: Climate and circulation anomalies in the South African region during the dry summer of 1982/1983, South African Weather Bureau, Pretoria, Tech. Paper 21, 45 pp.
Taljaard, J. J., Steyn, P. C. L., 1991: Relationships between atmospheric circulation and rainfall in the South African region, South African Weather Bureau, Pretoria, Tech. Paper 24, 62 pp.
Tyson, P. D., 1986:Climate Change and Variability in Southern Africa. Cape Town: Oxford Univ. Press, 220 pp.
Unganai, L. S., 1994: Surface temperature variation over Zimbabwe between 1897 and 1993, Drought Monitoring Centre, Harare, Tech. Rep., 14 pp.
Vowinckel, E., 1956: A review of the seasonal climatology of the southern Mozambique Channel region, Met Service Angola, Luanda, Tech. Rep., 63–86 pp.
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Jury, M.R., Majodina, M. Preliminary climatology of southern Africa extreme weather: 1973–1992. Theor Appl Climatol 56, 103–112 (1997). https://doi.org/10.1007/BF00863787
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DOI: https://doi.org/10.1007/BF00863787