Atmospheric transport of airborne material over and out of a region has important consequences for global change. In this article, recent developments concerning the transport of air, aerosols and trace gases in the troposphere over southern Africa will be examined. Regional circulation patterns affecting horizontal advection of aerosols and trace gases and the thermo dynamic controls modifying their vertical transport are considered. From trajectory dispersion fields, preferred transport pathways over and out of southern Africa are determined, as too is the extent of recirculation taking place over the subcontinent. Estimates of the mass fluxes of aerosols are given and the consequences of increasing aerosol loading in the atmosphere are examined.
Barclay, J.J., Jury, M.R. and Landman, W.1993: Climatological and structural differences between wet and dry troughs over southern Africa in early summer. Meteorology and AtmosphericPhysics51, 41-54.
2.
Browell, E.V.1993: TRACE-A airborne DIAL ozone and aerosol data. Hampton, VA: NASA/ Langley Research Center.
3.
Browning, K.A.1985: Conceptual models of precipitation systems. Meteorological Magazine114, 293-319.
4.
Carlson, T.N.1980: Airflow through mid-latitude cyclones and the comma cloud pattern. Monthly Weather Review108, 1498-509.
5.
Charlson, R.J., Langer, J. and Rohde, H.1990: Sulfate aerosol and climate. Nature326, 655-61.
Cosijn, C.1996: Stable discontinuities in the atmosphere over South Africa. Unpublished MSc dissertation, University of the Witwatersrand .
8.
Cosijn, C. and Tyson, P.D.1996: Stable discontinuities in the atmosphere over South Africa. South AfricanJournal of Science, 92, 381-86.
9.
Crutzen, P.J. and Andreae, M.O.1990: Biomass burning in the tropics: impact on atmospheric chemistry and biogeochemical cycles. Science250, 1669-78.
10.
D'Abreton, P.C.1993: The dynamics and energetics of tropical-temperate troughs over southern Africa. Unpublished PhD thesis, University of the Witwatersrand.
11.
— 1996: Lagrangian kinematic and isentropic trajectory models for aerosol and trace gas transport studies in southern Africa. South AfricanJournal of Science92, 157-60.
12.
D'Abreton, P.C. and Lindesay, J.A.1993: Water vapour transport over southern Africa during wet and dry late summer months. International Journal of Climatology13, 151-70.
13.
D'Abreton, P.C. and Tyson, P.D.1995: Divergent and non-divergent water vapour transport over southern Africa during wet and dry conditions. Meteorology and AtmosphericPhysics55, 47-59.
14.
— 1996: Three-dimensional kinematic trajectory modelling of water vapour transport over southern Africa. Water SA22, 297-306.
15.
D'Almeida, G.A.1987: Desert aerosol characteristics and effects on climate . In Leinen, M. and Sarnthein, M., editors, Palaeoclimatology and palaeometeorology: modern and past patterns of global atmospheric transport . Dordrecht: Kluwer Academic.
16.
Duce, R.A., Liss, P.L., Merrill, J.T., Atlas, E.L., Buat-Menard, P., Hicks, B.B., Miller, J.M., Prospero, J.M., Arimoto, R., Church, T.M., Ellis, W., Galloway, J.N., Hansen, L., Jickels, T.D., Knap, A.H., Reinhardt, K.H., Scheider, B., Soudine, A., Tokos, J.J., Tsunogai, S., Wollast, R. and Zhou, M.1991: The atmospheric input of trace species to the world ocean . Global Biogeochemical Cycles5, 193-259.
17.
Fishman, J.1991: Probing planetary pollution from space. Environmental Science and Technology25, 612-21.
18.
Fishman, J., Fakhruzzaman, K., Cros, B. and Mganga, D.1991: Identification of widespread pollution in the Southern Hemisphere deduced from satellite analyses. Science252, 1693-96.
19.
Fuelberg, H.E., Loring, R.O., Watson, M.V., Sinha, M.C., Pickering, K.E.,Thompson, A.M., Sachse, G.W., Blake, D.R. and Schoeberl, M.R.1996: TRACE-A trajectory intercomparison. Part 2. Isentropic and kinematic methods. Journal of Geophysical Research, 101, 23927-40.
20.
Garstang, M. and Tyson, P.D.1996: Atmospheric circulation, vertical structure and transport . In Van Wilgen, B., Andraea, M.O., Goldammer, J. and Lindesay, J.A., editors, Fire in southern African savannas: ecological and atmosphericpe perspectives . Johannesburg: Witwatersrand University Press.
21.
Garstang, M., Tyson, P.D., Browell, E. and Swap, R.1996a: Large scale transports of biogenic and biomass burning products. In Levine, J.S., editor, Biomass burning and global change. Cambridge, MA: MIT Press.
22.
Garstang, M., Tyson, P.D., Cachier, H. and Radke, L.1996b: Atmospheric transports of particulate and gaseous products by fire. In Clark, J., editor, Sediment records of biomass burning and global changeNew York: Springer-Verlag.
23.
Garstang, M., Tyson, P.D., Swap, R., Edwards, M., Kållberg, P. and Lindesay, J.A.1996c: Horizontal and vertical transport of air over southern Africa. Journal of Geophysical Research, 101, 23721-36.
24.
Grassl, H.1988: Radiative effects of atmospheric aerosol particles . In Hobbs, P.V. and McCormick, M.P., editors, Aerosols and climate . Hampton, VA: Deepak Publishing .
25.
Gregory, G.L., Fuelberg, H.E., Longmore, S.P., Anderson, B.E., Collins, J.E. and Blake, D.R.1996: Chemical characteristics of tropospheric air over the tropical South Atlantic Ocean: relationship to airmass source and trajectory history. Journal of Geophysical Research101, 23957-72.
26.
Harangoza, S. and Harrison, M.S.J.1983: On the use of synoptic data in indicating the presence of cloud bands over southern Africa. South AfricanJournal of Science79, 413-14.
27.
Harrison, M.S.J.1984: The annual rainfall cycle over the central interior of South Africa. South AfricanGeographical Journal66, 47-64.
28.
— 1986: A synoptic climatology of South African rainfall variations . Unpublished PhD thesis, University of the Witwatersrand .
29.
Helas, G., Andreae, M.O., Schebeske, G. and LeCanut, P.1995: SA'ARI-94: a preliminary view of results. South AfricanJournal of Science91, 360-62.
30.
Ipcc1996: Climate change: the second IPCC scientific assessment (Houghton, J. T., Meira Filho, L.G., Callander, B.A., Harris, N., Kattenberg, A. and Maskell, K., editors). Cambridge: Cambridge University Press.
31.
Jonas, P.R., Charlson, R.J. and Rodhe, H.1995: Aerosols. In Houghton, J. T., et al., editors, IPCC climate change 1994: radiative forcing of climate change. Cambridge: Cambridge University Press.
32.
Joubert, A.1994: Simulations of southern African climatic change by early-generation general circulation models. Water SA20, 315-22.
33.
— 1995: Simulations of southern African climate by early-generation general circulation models. South African Journal of Science191, 85-91.
34.
Joubert, A. and Tyson, P.D.1996: Equilibrium and coupled GCM simulations of future southern African climates. South AfricanJournal of Science , 471-84.
35.
Journal of Geophysical Research1996: Special issue on TRACE-A and SAFARI, 101, D19, October.
36.
Kållberg, P.1984: Air parcel trajectories from analysed or forecast windfields . Swedish Meteorological and Hydrological Institute Research and Development Note 37. Norrköping: SMHI .
37.
Krishnamurti, T.N., Fuelberg, H.E., Sinha, M.C., Oosterhof, D., Bensman, E.L. and Kumai, V.B.1993: The meteorological environment of the tropospheric ozone maximum over the tropical South Atlantic Ocean. Journal of Geophysical Research98, 10621-41.
38.
LeCanut, P., Andreae, M.O., Harris, G.W., Wienhold, F.G. and Zenker, T.1996: Aerosol optical properties over southern Africa during SAFARI-92. In Levine, J.S., editor, Biomass burning and global change. Cambridge, MA: MIT Press.
39.
Levine, J.S.1991: Global biomass burning: atmospheric, climate and biospheric implications. Cambridge, MA: MIT Press.
40.
Lindesay, J.A. and Jury, M.R.1991: Atmospheric circulation controls and characteristics of a flood event over southern Africa. International Journal of Climatology11, 609-27.
41.
Maenhaut, W., Salma, I., Annegarn, H.J. and Andreae, M.O.1996: Regional atmospheric composition and sources in the eastern Transvaal, South Africa and the impact of biomass burning. Journal of Geophysical Research, 101, 23631-50.
42.
Maenhaut, W., Salma, I., Garstang, M. and Meixner, F.1993: Size-fractionated atmospheric aerosol composition and aerosol sources at Etosha, Namibia and Victoria Falls, Zimbabwe. Paper presented at the 1993 AGU fall meeting, San Francisco, December.
43.
Mitchell, J.F.B., Davis, R.A., Ingram, W.J. and Senior, C.A.1995a: On surface temperature, greenhouse gases and aerosols: models and observations. Journal of Climate8, 2364-86.
44.
Mitchell, J.F.B. and Johns, T.C.1997: On the modification of global warming by sulphate aerosols . Journal of Climate, in press.
45.
Mitchell, J.F.B., Johns, T.C., Gregory, J.M. and Tett, S.B.F.1995b: Climate response to increasing levels of greenhouse gases and sulphate aerosols. Nature376501-504.
46.
Moody, J.L., Pszenny, A.A.P., Grandy, A., Keene, W.C., Galloway, J.N. and Polian, G.1991: Precipitation composition and its variability in the southern Indian Ocean: Amsterdam Island, 1980-1987. Journal of Geophysical Research96, 20769-86.
47.
Penner, J.E., Charlson, R.J., Hales, J.M., Lauleinen, N., Leifer, R., Novakov, T., Ogren, J., Radke, L.F., Schwartz, S.E. and Travis, L.1994: Quantifying and minimizing uncertainty of climate forcing by anthropogenic aerosols. Bulletin of the American Meteorological Society75, 375-400.
48.
Pickering, K.E., Thompson, A.M., McNarmara, D.P. and Schoeberl, M.R.1994a: An inter-comparison of isentropic trajectories over the South Atlantic. Monthly Weather Review122, 864-79.
49.
Pickering, K.E., Thompson, A.M., McNamara, D.P., Schoeberl, M.R., Fuelberg, H.E., Loring, R.O., Watson, M.V., Fakhruzzaman, K. and Bachmeier, A.S.1996: TRACE-A trajectory intercomparison. Part 1. Effects of different input analyses. Journal of Geophysical Research , 101, 23909-26.
50.
Pickering, K.E., Thompson, A.M., McNamara, D.P., Schoeberl, M.R., Lait, L.R., Newman, P.A., Justice, C.O. and Kendal, J.D.1994b: A trajectory modeling investigation of the biomass burning tropical ozone relationship. In Proceedings of the Quadrennial Ozone Symposium. NASA Conference Publication 3266, 101-104.
51.
Piketh, S.J.1995: Generation and transportation characteristics of suspended particles in the eastern Transvaal. Unpublished MSc dissertation , University of the Witwatersrand.
52.
Piketh, S.J., Annegam, H.J. and Kneen, M.A.1996: Regional scale impacts of biomass burning emissions over southern Africa. In Levine, J.S., editor, Biomass burning and global change. Cambridge, MA: MIT Press.
53.
Preston-Whyte, R.A. and Tyson, P.D.1989: The atmosphere and weather of southern Africa. Cape Town: Oxford University Press.
54.
Rayner, P.J. and Law, R.M.1995: A comparison of modelled responses to prescribed CO 2 sources. CSIRO Australia, Division of Atmospheric Research, Technical Paper 36. Mordialloc: CSIRO.
55.
Rorich, R.P. and Turner, C.R.1994: Ambient monitoring network annual data report for 1993 and regional trend analysis. Report TRR/S94/059/rw. Johannesburg : TRI, ESKOM.
56.
Schulze, B.R.1965. Climate of South Africa. Part 8. General survey (WB 28)Pretoria: South African Weather Bureau.
57.
Swap, R.J.1996: Transport and impact of southern African aerosols. Unpublished PhD dissertation, University of Virginia.
58.
Swap, R., Garstang, M., Macko, S.A., Tyson, P.D., Maenhaut, W., Artaxo, P., Kållberg, P. and Talbot, R.1996b: The long-range transport of southern African aerosols to the tropical South Atlantic. Journal of Geophysical Research101, 23777-93.
59.
Swap, R., Garstang, M., Macko, S.A., Tyson, P.D. and Kallberg, P.1996a: Comparison of biomass burning emissions and biogenic emissions to the tropical South Atlantic. In Levine, J.S., editor, Biomass burning and global change . Cambridge, MA: MIT Press.
60.
Talbot, R.W., Bradshaw, J.D., Sandholm, S., Smyth, S., Blake, D.R., Blake, N., Sachse, G.W., Collins, J., Heikes, B.G., Anderson, B.E., Gregory, G.L., Singh, H.B., Lefer, B.L. and Bachmeier, A.S.1996: Chemical characteristics of continental outflow over the tropical South Atlantic Ocean from Brazil and Africa. Journal of Geophysical Research101, 24187-202.
61.
Taljaard, J.J.1953: The mean circulation in the lower troposphere over southern Africa. South AfricanGeographical Journal35, 33-45.
62.
— 1972: Synoptic meteorology of the Southern Hemisphere. In Newton, C.W., editor, Meteorology of the Southern Hemisphere. Meteorological Monographs 35, Boston, MA: American Meteorological Society.
63.
— 1985: Cut-off lows in the South African region. South African Weather Bureau Technical Paper 14. Pretoria: SAWB.
64.
Taljaard, J.F. and Zunckel, M.1992: Comparative study of pollutants in the easternTransvaal. Pretoria: EMATEK/ CSIR.
65.
Taylor, K.E. and Penner, J.E.1994: Response of the climate to atmospheric aerosols and greenhouse gases. Nature369, 734-37.
66.
Thompson, A.M.1996: Evaluation of biomass burning effects on ozone during SAFARI/ TRACE-A: examples from the process models. In Levine, J.S., editor, Biomass burning and global change . Cambridge, MA: MIT Press.
67.
Thompson, A.M., Diab, R.D., Bodeker, G.E., Zunckel, M., Coetzee, G.J.R., Archer, C.B., McNamara, D.P., Pickering, K.E., Combrink, J.B., Fishman, J. and Nganga, D.1996a: Ozone over southern Africa during SAFARI-92/TRACE-A . Journal of Geophysical Research101, 23793-808.
68.
Thompson, A.M., Zenker, T., Gregory, E., Bodeker, G. and McNamara, D.P.1996b: Ozone over southern Africa: patterns and influences . In Van Wilgen, B., Andraea, M.O., Goldammer, J. and Lindesay, J.A., editors, Fire in southern African savannas: ecological and atmospheric perspectives . Johannesburg: Witwatersrand University Press.
69.
Tyson, P.D.1986: Climatic change and variability in southern Africa . Cape Town: Oxford University Press.
70.
Tyson, P.D. and D'Aberton, P.C.1997: Transport and recirculation of aerosols off southern Africa: macroscale plume structure. Atmospheric Environment , submitted.
71.
Tyson, P.D., Garstang, M. and Swap, R.1996a. Large-scale recirculation of air over southern Africa . Journal of Applied Meteorology, 35, 2218-36.
72.
Tyson, P.D., Garstang, M., Swap, R., Browell, E.V., Diab, R.D. and Thompson, A.M.1996b: Transport and vertical structure of ozone and aerosol distributions over southern Africa. In Levine, J.S., editor, Biomass burning and global change . Cambridge, MA: MIT Press.
73.
Tyson, P.D., Garstang, M., Swap, R., Kållberg, P. and Edwards, M.1996c: An air transport climatology for subtropical southern Africa. International Journal of Climatology16, 265-91.
74.
Tyson, P.D., Kruger, F.J. and Louw, C.W.1988: Atmospheric pollution and its implications in the Eastern Transvaal Highveld. South African National Scientific Programmes Report 150. Pretoria: Foundation for Research Development .
75.
Tyson, P.D., Gasse, F., Bergonzini, L. and D'Aberton, P.C.1997: Aerosols, atmospheric transmissivity and hydrological modelling of climate change over Africa south of the equator. International Journal of Climatology, submitted.
76.
van den Heever, S.C.1995: Modelling tropical-temperate troughs over southern Africa. Unpublished MSc dissertation, University of the Witwatersrand .
77.
Watson, C.E., Fishman H. and Reichle, H.J., 1990: The significance of biomass burning as a source of carbon monoxide and ozone in the Southern Hemisphere tropics: a satellite analysis . Journal of Geophysical Research95, 16433-50.
78.
Wells, R.B., Snyman, G.M., Held, G. and Dos Santos, A.1987: Air pollution on the Eastern Transvaal Highveld . Foundation for Research Development Report CSIR Atmos/87/23. Pretoria : Atmospheric Sciences Division, NPRL, CSIR .
79.
Zenker, T., Thompson, A.M., McNamara, D.P., Kucsera, T.L., Harris, F.G., Wienhold, F.G., LeCanut, P., Andreae, M.O. and Koppman, R.1996: Regional trace gas distribution and airmass characteristics in the haze layer over southern Africa during the biomass burning season (Sept/ Oct 92): observations and modeling from the STARE/SAFARI '92 DC3. In Levine, J.S., editor, Biomass burning and global change. Cambridge, MA: MIT Press.
