Editorial Type:
Article
Article Type:
Research Article

Distribution and Statistics of African Mesoscale Convective Weather Systems Based on the ISCCP Meteosat Imagery

K. I. Hodges Environmental Systems Science Centre and Centre for Global Atmospheric Modeling,University of Reading, Reading, United Kingdom

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C. D. Thorncroft Department of Meteorology, University of Reading, Reading, United Kingdom

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Print Publication:
01 Nov 1997
DOI:
https://doi.org/10.1175/1520-0493(1997)125<2821:DASOAM>2.0.CO;2
Page(s):
2821–2837
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Abstract

This paper provides for the first time an objective short-term (8 yr) climatology of African convective weather systems based on satellite imagery. Eight years of infrared International Satellite Cloud Climatology Project–European Space Agency’s Meteorological Satellite (ISCCP–Meteosat) satellite imagery has been analyzed using objective feature identification, tracking, and statistical techniques for the July, August, and September periods and the region of Africa and the adjacent Atlantic ocean. This allows various diagnostics to be computed and used to study the distribution of mesoscale and synoptic-scale convective weather systems from mesoscale cloud clusters and squall lines to tropical cyclones. An 8-yr seasonal climatology (1983–90) and the seasonal cycle of this convective activity are presented and discussed. Also discussed is the dependence of organized convection for this region, on the orography, convective, and potential instability and vertical wind shear using European Centre for Medium-Range Weather Forecasts reanalysis data.

Corresponding author address: Dr. K. I. Hodges, ESSC (Environmental Systems Science Centre), University of Reading, Whiteknights, P.O. Box 227, Reading RG6 6AB, United Kingdom.

Abstract

This paper provides for the first time an objective short-term (8 yr) climatology of African convective weather systems based on satellite imagery. Eight years of infrared International Satellite Cloud Climatology Project–European Space Agency’s Meteorological Satellite (ISCCP–Meteosat) satellite imagery has been analyzed using objective feature identification, tracking, and statistical techniques for the July, August, and September periods and the region of Africa and the adjacent Atlantic ocean. This allows various diagnostics to be computed and used to study the distribution of mesoscale and synoptic-scale convective weather systems from mesoscale cloud clusters and squall lines to tropical cyclones. An 8-yr seasonal climatology (1983–90) and the seasonal cycle of this convective activity are presented and discussed. Also discussed is the dependence of organized convection for this region, on the orography, convective, and potential instability and vertical wind shear using European Centre for Medium-Range Weather Forecasts reanalysis data.

Corresponding author address: Dr. K. I. Hodges, ESSC (Environmental Systems Science Centre), University of Reading, Whiteknights, P.O. Box 227, Reading RG6 6AB, United Kingdom.

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  • Arnaud. Y., M. Desbois, and J. Maizi, 1992: Automatic tracking and characterization of African convective systems on Meteosat pictures. J. Appl. Meteor.,31, 443–453.

  • Avila, L. A., and R. J. Pasch, 1992: Atlantic tropical systems of 1991. Mon. Wea. Rev.,120, 2688–2696.

  • Carlson, T. N., 1969: Some remarks on African disturbances and their progress over the tropical Atlantic. Mon. Wea. Rev.,97, 716–726.

  • Chong, M., P. Amayenc, G. Scialom, and J. Testud, 1987: A tropical squall line observed during the COPT 81 experiment in West Africa. Part I: Kinematic structure inferred from dual Doppler radar data. Mon. Wea. Rev.,115, 670–694.

  • Desbois, M., T. Kayiranga, B. Gnamien, S. Guessous, and L. Picon, 1988: Characterization of some elements of the Sahelian climate and their interannual variations for July 1983, 1984, and 1985 from the analysis of METEOSAT ISCCP data. J. Climate,1, 867–904.

  • Emanuel, K. A., 1994: Atmospheric Convection. Oxford University Press, 580 pp.

  • Hastenrath, S., 1991: Climate Dynamics of the Tropics. Kluwer Academic Publishers, 488 pp.

  • Hodges, K. I., 1994: A general method for tracking analysis and its application to meteorological data. Mon. Wea. Rev.,122, 2573–2586.

  • ——, 1995: Feature tracking on the unit sphere. Mon. Wea. Rev.,123, 3458–3465.

  • ——, 1996: Spherical nonparametric estimators applied to the UGAMP GCM integration for AMIP. Mon. Wea. Rev.,124, 2914–2932.

  • Laing, A. G., and J. M. Fritsch, 1993: Mesoscale convective complexes in Africa. Mon. Wea. Rev.,121, 2254–2263.

  • Landsea, C., and W. M. Gray, 1992: The strong association between western Sahel monsoon rainfall and intense Atlantic hurricanes. J. Climate,5, 435–453.

  • Machado, L. A. T., J. P. Duval, and M. Desbois, 1993: Diurnal variations and modulations by easterly waves of the size distribution of convective cloud clusters over West Africa and the Atlantic Ocean. Mon. Wea. Rev.,121, 37–49.

  • Maddox, R. A., 1980: Mesoscale convective complexes. Bull. Amer. Meteor. Soc.,61, 1374–1387.

  • Nicholson, S. E., 1980: The nature of rainfall fluctuations in subtropicalWest Africa. Mon. Wea. Rev.,108, 473–487.

  • Reed, R. J., D. C. Norquist, and E. E. Recher, 1980: Origin of African wave disturbances during Phase III of GATE. Mon. Wea. Rev.,108, 1827–1839.

  • Rossow, W. B., E. Kinsella, and A. Wolf, 1987: International Satellite Cloud Climatology Project (ISCCP) description of reduced resolution radiance data. World Meteorological Organization WMO/TD-No. 58, 143 pp.

  • Rowell, D. P., and J. R. Milford, 1993: On the generation of African squall lines. J. Climate,6, 1181–1193.

  • ——, C. K. Folland, K. Maskell, and M. N. Ward, 1995: Variability of summer rainfall over tropical north Africa (1906–92): Observations and modelling. Quart. J. Roy. Meteor. Soc.,121, 669–704.

  • Thorncroft, C. D., and M. Haile, 1995: The mean dynamic and thermodynamic fields for July 1989 over tropical north Africa and their relationship to convective activity. Mon. Wea. Rev.,123, 3016–3031.

  • Weisman, M. L., and J. B. Klemp, 1982: The dependence of numerically simulated convective storms on vertical shear and bouyancy. Mon. Wea. Rev.,110, 504–520.

  • Williams, E., and N. Renno, 1993: An analysis of the conditional instability of the tropical atmosphere. Mon. Wea. Rev.,121, 21–36.

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