Summary
Distributions through the year of temperature, geopotential height and specific humidity, and of their standard deviations, over southern African radiosonde stations are studied through harmonic analysis. Characteristics of annual and semi-annual cycles vary across the subcontinent as a result of thermal and mechanical effects induced by the land mass. Over the interior plateau temperatures and geopotential heights through to 100 hPa respond directly to solar heating of the surface and resultant seasonal changes in surface-at-mosphere heat fluxes. Around the coast temperatures and geopotential heights are additionally influenced by seasonally-varying ocean-atmosphere heat fluxes. Cycles of atmospheric moisture are dependent on properties of the low-level circulation rather than on temperature per se. The results demarcate the two inversions frequently located over the subcontinent and indicate that the local subtropical jet stream is displaced latitudinally on a semi-annual cycle, lying furthest south in February and August.
Similar content being viewed by others
References
Anh, N. N., Gill, A. E., 1981: Generation of coastal lows by synoptic-scale waves.Quart. J. Roy. Meteor. Soc. 107, 521–530.
Bannon, P. R., 1981: Synoptic-scale forcing of coastal lows: forced double Kelvin waves in the atmosphere.Quart. J. Roy. Meteor. Soc. 107, 313–327.
Christensen, M. S., 1980: Sea-surface temperature charts for southern Africa, south of 26°S.South African J. Sci. 76, 541–546.
De Wet, L. W., 1983: The influence of the southern African orography on the development and propogation of atmospheric disturbances. Preprints of the 1st International Conference on Southern Hemisphere Meteorology. American Meteorological Society, 367–370.
Dyer, T. G. J., 1976: Meridional interactions between rainfall and surface pressure.Nature 264, 48–49.
Dyer, T. G. J., 1979: Rainfall along the east coast of southern Africa, the Southern Oscillation, and the latitude of the subtropical high pressure belt.Quart. J. Roy. Meteor. Soc. 105, 445–451.
Garstang, M., Kelbe, B. E., Emmitt, G. D., London, W. B., 1987: Generation of convective storms over the escarpment of northeastern South Africa.Mon. Wea. Rev. 115, 429–443.
Grundlingh, M. L., 1987: On the seasonal temperature variation in the southwestern Indian Ocean.South African Geogr. J. 69, 129–138.
Harrison, M. S. J., 1983: The Southern Oscillation, zonal equatorial circulation cells and South African rainfall. Preprints of the 1st International Conference on Southern Hemisphere Meteorology, American Meteorological Society, 302–305.
Harrison, M. S. J., 1984: The annual rainfall cycle over the central interior of South Arica.South African Geogr. J. 66, 47–64.
Harrison, M. S. J., 1986: A synoptic climatology of South African rainfall variations. Unpublished PhD Thesis, University of the Witwatersrand, 341 pp.
Harrison, M. S. J., 1988: Rainfall and precipitable water relationships over the central interior of South Africa.South African Geogr. J. 70, 100–111.
Harrison, M. S. J., 1991: Elevated inversions over southern Africa: climatological properties, formation processes and relationships with rainfall.South African Geogr. J., in print.
Harrison, M. S. J., Theron, G. F., 1991: Kinematic properties of the mean circulation over southern Africa.Theor. Appl. Climatol.,43, 75–90.
Hofmeyr, W. L., Gouws, V., 1964: A statistical and synoptic analysis of wet and dry conditions in the northwestern Transvaal.Notos 13, 37–48.
Howarth, D. A., 1983: Seasonal variation in the vertically integrated water vapor transport fields over the Southern Hemisphere.Mon. Wea. Rev. 111, 1259–1272.
Hsu, C-P. F., Wallace, J. M., 1976: The global distribution of the annual and semiannual cycles in sea level pressure.Mon. Wea. Rev. 104, 1597–1601.
Jackson, S. P., 1951: Climates of southern Africa.South African Geogr. J. 33, 17–37.
Jury, M. R., 1985: Mesoscale variations in summer winds over the Cape Columbine—St Helena Bay region, South Africa.South African J. Marine Sci. 3, 77–88.
Katsiambirtas, E. E., 1979:Upper-Air Statistics, Wind, Temperature, Geopotential and Humidity. Climate of South Africa: Part 13. WB39, South African Weather Bureau, 99 pp.
Kelbe, B., 1988: Features of westerly waves propagating over southern Africa during summer.Mon. Wea. Rev. 116, 60–70.
Labitzke, K., van Loon, H., 1972: The stratosphere in the Southern Hemisphere. In: Newton, C. W. (ed.):Meteorology of the Southern Hemisphere. (Meteorological Monographs 35, American Meteorological Society, Boston), 113–138.
Le Marshall, J. F., Kelly, G. A. M., Karoly, D. J., 1985: An atmospheric climatology of the Southern hemisphere based on ten years of daily numerical analyses (1972–82).Austral. Meteor. Mag. 33, 65–85.
Levitus, S., 1987: A comparison of the annual cycle of two sea surface temperature climatologies of the world ocean.J. Phys. Oceanogr. 17, 197–214.
Lindesay, J. A., 1988: Southern African rainfall, the Southern oscillation and a Southern hemisphere semi-annual cycle.J. Climatol. 8, 17–30.
Lindesay, J. A., Harrison, M. S. J., Haffner, M. P., 1986: The Southern oscillation and South African rainfall.South African J. Sci. 82, 196–198.
McGee, O. S., 1978: A note on the inter-annual consistency of atmospheric water vapour content over South Africa.South African Geogr. 6, 31–34.
McGee, O. S., 1986: The distribution of water vapour in the atmosphere over South Africa.South African Geogr. J. 68, 117–131.
McGee, O. S., Hastenrath, S.L., 1966: Harmonic analysis of the rainfall over South Africa.Notos 15, 79–90.
Newell, R. E., Kidson, J. W., Vincent, D. G., Boer, G. J., 1974:The General Circulation of the Tropical Atmosphere and Interactions with Extratropical Latitudes, Vol.2.Cambridge MIT Press, 371 pp.
Newton, C. W., 1972: Southern hemisphere general circulation in relation to global energy and momentum balance requirements. In:Meteorology of the Southern Hemisphere.(Meteorological Monographs 35, American Meteorological Society, Boston) 215–246.
Oort, A. H., Rasmusson, E. M., 1970: On the annual variation of the monthly mean meridional circulation.Mon. Wea. Rev. 98, 423–442.
Peixoto, J. P., Corte-Real, J. A. M., 1982: The energetics of the general circulation of the atmosphere in Southern hemisphere during the IGY. Part I: the distribution of atmospheric energy.Arch. Met. Geoph. Biocl., Serie A. 31, 277–301.
Peixoto, J. P., Oort, A. H., 1983: The atmospheric branch of the hydrological cycle and climate. In: Street-Perrott, A., Beran, M., Ratcliffe, R. (eds.):Variations in the Global Water Budget. Dordrecht: D.Reidel, 5–65.
Physick, W. L., 1981: Winter depression tracks and climatological jet streams in the Southern Hemisphere during the FGGE year.Quart. J. Roy. Meteor. Soc. 107, 883–898.
Prescott, J. A., Collins, J. A., 1951: The lag of temperature behind solar radiation.Quart. J. Roy. Meteor. Soc. 77, 121–126.
Preston-Whyte, R. A., Diab, R. D., Tyson, P. D., 1977: Towards an inversion climatology of southern Africa. Part 2: non-surface inversions in the lower atmosphere.South African Geogr. J. 59, 47–59.
Reed, R. J., Vlcek, C. J., 1969: The annual temperature variation in the lower tropical stratosphere.J. Atmos. Sci. 26, 163–167.
Rubin, M. J., 1956: The associated precipitation and circulation patterns over southern Africa.Notos 5, 53–59.
Schulze, B. R., 1960: Temperature fluctuation in South Africa.South African Geogr. J. 42, 3–22.
Stoeckenius, T., 1981: Interannual variations of tropical precipitation patterns.Mon. Wea. Rev. 109, 1233–1247.
Taljaard, J. J., 1981: Upper-air circulation, temperature and humidity over southern Africa. South African Weather Bureau Technical Paper 10, 94 pp.
Taljaard, J. J., 1986: Change of rainfall distribution and circulation patterns over southern Africa in summer.J. Climatol. 6, 579–592.
Taljaard, J. J., Schmitt, W., van Loon, H., 1961: Frontal analyses with application to the Southern Hemisphere.Notos 10, 25–58.
Theron, G. F., 1990: Annual and semi-annual cycles in atmospheric circulation over South Africa, 1968–1977. Unpublished MSc Dissertation, University of the Witwatersrand, 94 pp.
Theron, G. F., Harrison, M. S. J., 1991: The atmospheric circulation over Gough and Marion Islands.South African J. Sci.,87, in print.
Trenberth, K. E., 1981: Observed Southern Hemisphere eddy statistics at 500 mb: frequency and spatial distribution.J. Atmos. Sci. 38, 2585–2605.
Trenberth, K. E., 1982: Seasonality in Southern Hemisphere eddy statistics at 500 mb.J. Atmos. Sci. 39, 2507–2520.
Trenberth, K. E., 1986: The signature of a blocking episode on the general circulation in the Southern Hemisphere.J. Atmos. Sci. 43, 2061–2069.
Triegaardt, D. O., Kraus, G. M. E., 1957: An example of wave disruption over southern Africa.Notos 6, 6–12.
Tyson, P. D., 1964: Berg winds of South Africa.Weather 19, 7–11.
Tyson, P. D., 1984: The atmospheric modulation of extended wet and dry spells over South Africa, 1958–1978.J. Climatol. 4, 621–635.
Van Loon, H., 1972a: Temperature in the Southern Hemisphere. In: Newton, C. W., (ed.):Meteorology of the Southern Hemisphere. (Meteorological Monographs 35, American Meteorological Society, Boston), 25–58.
Van Loon, H., 1972b: Pressure in the Southern Hemisphere. In: Newton, C. W. (ed.):Meteorology of the Southern Hemisphere. (Meteorological Monographs 35, American Meteorological Society, Boston), 59–86.
Van Loon, H., Jenne, R. L., 1969: The half-yearly oscillations in the tropics of the Southern Hemisphere.J. Atmos. Sci. 26, 218–232.
Van Loon, H., Jenne, R. L., 1970: The annual wave in the temperature of the low stratosphere.J. Atmos. Sci. 27, 701–705.
Van Loon, H., Jenne, R. L., Taljaard, J. J., Crutcher, H. L., 1968: An outline of the yearly and half-yearly components in the zonal mean temperature and wind between the surface and 100 mb in the Southern Hemisphere.Notos 17, 53–62.
Van Loon, H., Rogers, J. C., 1984: The yearly wave in pressure and zonal geostrophic wind at sea level on the Southern Hemisphere and its interannual variability.Tellus 36 A, 348–354.
Van Loon, H., Taljaard, J. J., 1958: A study of the 1000-500 mb thickness distribution in the Southern Hemisphere.Notos 7, 123–158.
Van Rooy, M. P., 1936: Influence of berg winds on the temperatures along the west coast of South Africa.Quart. J. Roy. Meteor. Soc. 62, 528–537.
Vianello, R. L., 1985: Vertical velocity forced by topography in the Southern Hemisphere.J. Climatol. 5, 213–219.
White, G. H., Wallace, J. M., 1978: The global distribution of the annual and semiannual cycles in surface temperature.Mon. Wea. Rev. 106, 901–906.
Author information
Authors and Affiliations
Additional information
With 12 Figures
Rights and permissions
About this article
Cite this article
Theron, G.F., Harrison, M.S.J. Thermodynamic properties of the mean circulation around southern Africa. Theor Appl Climatol 43, 161–174 (1991). https://doi.org/10.1007/BF00867451
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00867451