Theoretical and Applied Climatology

, Volume 48, Issue 4, pp 187–194 | Cite as

Evolution and variability of the ITCZ in the SW Indian Ocean: 1988–90

  • M. R. Jury
  • B. Parker
  • D. Waliser


The structure and variability of the inter-tropical convergence zone (ITCZ) in the SW Indian Ocean in the austral summer is investigated. The ITCZ is identified by satellite microwave (SSMI) precipitable water (PW) values > 5 g cm−2, minimum outgoing longwave radiation (OLR) values < 220 W m−2 and the pattern of convergence in the low level (850 hPa) winds. According to OLR climatology, the ITCZ lies over 15°S latitude to the west of Madagascar (40–50°E), but near 10°S to the east of 60°E. Inter-annual and intra-seasonal variability is induced by the interaction of the convective NW monsoon and subsident easterly trades. Symptoms of the structure and variability are presented using tropical cyclone (TC) tracks, axes of PW exceedences and OLR, 850hPa wind and PW fields in the period 1988–1990. The shape and intensity of the ITCZ is modulated by the strength of the NW monsoon off east Africa and by standing vortices in the SW Indian Ocean. The topography of Madagascar imparts a distinctive break in convective characteristics, and distinguishes the SE African ITCZ from its maritime counterpart.


Vortex Waste Water Microwave Water Pollution Cyclone 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Anyamba, E. K., 1992: Some properties of a 20–30 day oscillation in tropical convection.J. Afr. Met. Soc., Nairobi,1, 1–19.Google Scholar
  2. Chen, T.-C., Tzeng, R.-Y., 1990: Global scale intraseasonal and annual variation of divergent water-vapour flux.Meteorol. Atmos. Phys.,44, 133–151.Google Scholar
  3. Chiu, L. S., Chang, A. T. C., Janowiak, J., 1993: Comparison of monthly rain rates derived from GPR and SSMI using probability distribution functions.J. Appl. Meteor.,32, 323–334.Google Scholar
  4. Climate Analysis Center, 1988–1990:Climate Diagnostics Bulletin. NOAA Tech Rep, Washington DC.Google Scholar
  5. Ecormier, J., 1992: Tropical cyclones of the SW Indian Ocean, cases affecting Reunion Island.Tech. Rep., Meteo France, St Clotilde, Reunion, 479 pp.Google Scholar
  6. Jury, M. R., Pathack, B. M. R., 1991: A study of climate and weather variability over the tropical SW Indian Ocean.Meteorol. Atmos. Phys.,47, 37–48.Google Scholar
  7. Jury, M. R., Pathack, B., Campbell, G., Wang, B., Landman, W., 1991: Transient convective waves in the tropical SW Indian Ocean.Meteorol. Atmos. Phys.,47, 27–36.Google Scholar
  8. Jury, M. R., Waliser, D., 1991: Satellite microwave measurements of atmospheric water vapour and marine wind speed, case study applications.S. Afr. J. Mar. Sci.,9, 309–316.Google Scholar
  9. Jury, M. R., Pathack, B., Legler, D., 1992: The structure and variability of surface circulation anomalies, in the SW Indian Ocean in the austral summer.S. Afr. J. Mar. Sci.,11, 1–14.Google Scholar
  10. Jury, M. R., Pathack, B., Waliser, D., 1993a: Satellite OLR and microwave data as a proxy for rainfall in the southern Africa — Madagascar region.Int. J. Climatol.,13, 257–269.Google Scholar
  11. Jury, M. R., Pathack, B. M. R., 1993: Composite climatic patterns associated with extreme modes of summer rainfall over southern Africa.Theor. Appl. Climatol.,47, 137–145.Google Scholar
  12. Jury, M. R., 1993: A preliminary study of climatological associations and characteristics of tropical cyclones in the SW Indian Ocean.Meteorol. Atmos. Phys.,51, 101–115.Google Scholar
  13. Jury, M. R., Levey, K., McQueen, C., Parker, B., Lee-Thorpe, A., Makarau, A., Pathack, B., 1993b: Correlation atlas of climatic determinants for sub-tropical southern Africa and the SW Indian Ocean.Tech. Rep., Oceanogr Dept. Univ. Cape Town, 172 pp.Google Scholar
  14. Jury, M. R., Parker, B., Raholijao, N., Nassor, A., 1993c: Variability of summer convection over Madagascar: climatic determinants at inter-annual scales.Int. J. Climatol. (submitted).Google Scholar
  15. Lindesay, J., Jury, M. R., 1991: Atmospheric controls and characteristics of a flood event in central South Africa.Int. J. Climatol.,11, 609–627.Google Scholar
  16. Padya, B. M., 1989:Weather and Climate of Mauritius. Mauritius: M Gandhi Inst. 283 pp.Google Scholar
  17. Vermuelen, J. H., Jury, M. R., 1992: Tropical cyclones in the SW Indian Ocean, track prediction and verification 1989–1991.Meteorol. Mag.,121, 186–192.Google Scholar
  18. Wang, B., Rui, H., 1990: Synoptic climatology of transient tropical intra-seasonal convective anomalies: 1975–1984.Meteorol. Atmos. Phys.,44, 43–61.Google Scholar
  19. Wentz, E. J., 1989:User's Manual SSMI Geophysical Tapes. Remote Sensing Systems, California, 120 pp.Google Scholar
  20. Williams, J. B., 1990: Some temporal and regional variations of climate in Madagascar.Tech. Rep., Overseas Dev Nat Res Inst, Chatham Marine, Kent, 147 pp.Google Scholar
  21. Williams, E., Renno, N., 1993: An analysis of the conditional instability of the tropical atmosphere.Mon. Wea. Rev.,121, 21–36.Google Scholar
  22. Zhu, B., Wang, B., 1993: The 30–60 day convection see-saw between the tropical Indian and western Pacific Oceans.J. Atmos. Sci.,50/2, 184–199.Google Scholar

Copyright information

© Springer-Verlag 1994

Authors and Affiliations

  • M. R. Jury
    • 1
  • B. Parker
    • 1
  • D. Waliser
    • 2
  1. 1.Oceanography DepartmentUniversity of Cape TownRondeboschSouth Africa
  2. 2.University of CaliforniaLos AngelesUSA

Personalised recommendations