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Intra-seasonal rainfall oscillations over central Africa: space-time character and evolution

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Summary

The spatial and temporal structure of intra-seasonal oscillations over central Africa are investigated using 21 years (1980–2000) of pentad (5 day) rainfall and low level wind. The dominant mode for intra-seasonal rainfall is over the northern Congo River basin with a period of oscillation of 40–50 days. The second and third rainfall modes are over the southwest Congo/Angola and East African highlands, respectively. The leading zonal wind modes are situated over the Gulf of Guinea and West Indian Ocean. Cross correlation reveals that wet spells over the Congo and eastern Africa are related to increased westerly flow over the Atlantic. These start to develop a few pentads before the rainfall event. For Congo rainfall oscillations above a prescribed threshold in JJAS season, composite patterns suggest that eastward propagation is more pronounced in the kinematic field (velocity potential) than in the convection (OLR). The annual cycle is represented as an increase in amplitude of phase-locked intraseasonal events.

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References

  • Agumba FO (1985) Fluctuation of long rains in Kenya in relation to large scale circulation. IMTR Nairobi, Kenya Res Report, Vol. 85, 27 pp

  • Bjornsson H, Venegas SA (1997) A manual for EOF and SVD Analysis of climatic Data, 1997. CCGCR Report 97: 50–52

  • DJ Cecil EJ Zipser SW Nesbitt (2005) ArticleTitle3 years of TRMM precipitation features: radiometric and lightning characteristics Mon Wea Rev 133 543–566 Occurrence Handle10.1175/MWR-2876.1

    Article  Google Scholar 

  • T Chen M Murakami (1988) ArticleTitleThe 30–50 day variation of convective activity over the western Pacific Ocean with the emphasis on the northwestern region Mon Wea Rev 116 892–906 Occurrence Handle10.1175/1520-0493(1988)116<0892:TDVOCA>2.0.CO;2

    Article  Google Scholar 

  • S Gollmer RF Harshvardhan Cahalan JB Snider (1995) ArticleTitleWindowed and wavelet analysis of marine stratocumulus cloud inhomogeneity J Atmos Sci 52 3013–3030 Occurrence Handle10.1175/1520-0469(1995)052<3013:WAWAOM>2.0.CO;2

    Article  Google Scholar 

  • HH Hendon ML Salby (1994) ArticleTitleThe life cycle of the Madden Julian oscillation J Atmos Sci 51 2225–2237 Occurrence Handle10.1175/1520-0469(1994)051<2225:TLCOTM>2.0.CO;2

    Article  Google Scholar 

  • Q Hu DA Randall (1994) ArticleTitleLow frequency oscillations in radiative-convective systems J Atmos Sci 51 1089–1099 Occurrence Handle10.1175/1520-0469(1994)051<1089:LFOIRC>2.0.CO;2

    Article  Google Scholar 

  • J Huang H Cho (1998) ArticleTitleSeasonal modulated intra-seasonal oscillations in a GCM simulation Int J Climatol 18 1521–1532 Occurrence Handle10.1002/(SICI)1097-0088(19981130)18:14<1521::AID-JOC319>3.0.CO;2-1

    Article  Google Scholar 

  • Jury MR (2007) A comparison of low and high frequency climate factors influencing river flows in southern Angola, (submitted)

  • SR Kemball-Cook B Wang (2001) ArticleTitleEquatorial waves and air sea interaction in the boreal summer intra-seasonal oscillation J Climate 14 2923–2942 Occurrence Handle10.1175/1520-0442(2001)014<2923:EWAASI>2.0.CO;2

    Article  Google Scholar 

  • KM Lau HY Weng (1995) ArticleTitleClimate signal detection using wavelet transform. How to make a time series sing Bull Amer Meteor Soc 76 2391–2402 Occurrence Handle10.1175/1520-0477(1995)076<2391:CSDUWT>2.0.CO;2

    Article  Google Scholar 

  • RA Madden PR Julian (1971) ArticleTitleDetection of a 40–50 day oscillation in the zonal wind in the tropical Pacific J Atmos Sci 28 702–708 Occurrence Handle10.1175/1520-0469(1971)028<0702:DOADOI>2.0.CO;2

    Article  Google Scholar 

  • RA Madden PR Julian (1972) ArticleTitleDescription of global-scale circulation cell in the tropics with a 40–50 day period J Atmos Sci 29 1109–1123 Occurrence Handle10.1175/1520-0469(1972)029<1109:DOGSCC>2.0.CO;2

    Article  Google Scholar 

  • RA Madden PR Julian (1994) ArticleTitleObservations of the 40–50 day tropical oscillation: a review Mon Wea Rev 122 814–837 Occurrence Handle10.1175/1520-0493(1994)122<0814:OOTDTO>2.0.CO;2

    Article  Google Scholar 

  • RA Madden DJ Shea GW Branstator JJ Tribbia R Weber (1993) ArticleTitleThe effects of imperfect spatial and temporal sampling on estimates of the global mean temperature: experiments with model data J Climate 6 1057–1066 Occurrence Handle10.1175/1520-0442(1993)006<1057:TEOISA>2.0.CO;2

    Article  Google Scholar 

  • JR McCollum RA Gruber MB Ba (2000) ArticleTitleDiscrepancy between gauge and satellite estimates of rainfall over equatorial Africa J Appl Meteor 39 666–679 Occurrence Handle10.1175/1520-0450-39.5.666

    Article  Google Scholar 

  • GR McGregor S Niewolt (1998) Tropical climatology SeriesTitleAn introduction to the climates of low latitudes Wiley Inc. New York 339

    Google Scholar 

  • SD Meyers BG Kelley JJ O’Brien (1993) ArticleTitleAn introduction to wavelet analysis in oceanography and meteorology: with application to the dispersion of Yania waves Mon Wea Rev 121 2858–2866 Occurrence Handle10.1175/1520-0493(1993)121<2858:AITWAI>2.0.CO;2

    Article  Google Scholar 

  • JR Milford G Dugdale (1990) Estimation of rainfall using geostationary satellite data MD Steven JA Clark (Eds) Application of remote sensing in agriculture Butterworths London 97–110

    Google Scholar 

  • F Mounier S Janicot (2004) ArticleTitleEvidence of two independent modes of convection at intraseasonal timescale in the West African summer monsoon Geophys Res Lett 31 L16116 Occurrence Handle10.1029/2004GL020665

    Article  Google Scholar 

  • JE Mpeta MR Jury (2001) ArticleTitleIntra-seasonal convective structure and evolution over tropical east Africa Climate Res 17 83–92 Occurrence Handle10.3354/cr017083

    Article  Google Scholar 

  • Mulenga HM (1998) Southern African climatic anomalies, summer rainfall and the Angola low. Ph.D. thesis, Oceanogr Dept. Univ., Cape Town, 261 pp

  • CC Mutai MN Ward (2000) ArticleTitleEast African rainfall and tropical circulation/convection on intra-seasonal to inter-annual time scales J Climate 13 3915–3939 Occurrence Handle10.1175/1520-0442(2000)013<3915:EARATT>2.0.CO;2

    Article  Google Scholar 

  • RE Okoola (1999) ArticleTitleA diagnostic study of the east African monsoon circulation during the northern hemisphere spring season Int J Climate 19 143–168 Occurrence Handle10.1002/(SICI)1097-0088(199902)19:2<143::AID-JOC342>3.0.CO;2-U

    Article  Google Scholar 

  • H Rui B Wang (1990) ArticleTitleDevelopment characteristics and Dynamic structure of tropical intra-seasonal convective anomalies J Atmos Sci 47 357–379 Occurrence Handle10.1175/1520-0469(1990)047<0357:DCADSO>2.0.CO;2

    Article  Google Scholar 

  • ML Salby HH Hendon (1994) ArticleTitleIntra-seasonal behavior of clouds, temperature and motion in the tropics J Atmos Sci 51 2207–2224 Occurrence Handle10.1175/1520-0469(1994)051<2207:IBOCTA>2.0.CO;2

    Article  Google Scholar 

  • KR Sperber (2004) ArticleTitleMadden-Julian variability in NCAR CAM and CCSM models Clim Dynam 23 IssueID3–4 259–278

    Google Scholar 

  • Tazalilka L (2003) Satellite derived rainfall over tropical Africa, its pattern, variability and calibration. MSc thesis, Univ Zululand, 150 pp

  • EK Vizy KH Cook (2003) ArticleTitleConnection between the summer east African and Indian rainfall regimes J Geophys Res 108 IssueIDD16 247–285 Occurrence Handle10.1029/2003JD003452

    Article  Google Scholar 

  • DE Waliser C Jones JE Schemm N Graham (1999) ArticleTitleA statistical extended range tropical model based on the slow evolution of the Madden-Julian oscillation J Climate 12 1918–1939 Occurrence Handle10.1175/1520-0442(1999)012<1918:ASERTF>2.0.CO;2

    Article  Google Scholar 

  • HY Weng KM Lau (1994) ArticleTitleWavelet period doubling and time frequency localization with application to satellite data analysis J Atmos Sci 51 2523–2541 Occurrence Handle10.1175/1520-0469(1994)051<2523:WPDATL>2.0.CO;2

    Article  Google Scholar 

  • M Wheeler GN Kiladis PJ Webster (2000) ArticleTitleLarge-scale dynamical fields associated with convectively coupled equatorial waves J Atmos Sci 57 613–640 Occurrence Handle10.1175/1520-0469(2000)057<0613:LSDFAW>2.0.CO;2

    Article  Google Scholar 

  • P Xie PA Arkin (1997) ArticleTitleGlobal precipitation: a 17 year monthly analysis based on gauge observations, satellite estimates, and numerical model outputs Bull Amer Meteor Soc 78 2539–2558 Occurrence Handle10.1175/1520-0477(1997)078<2539:GPAYMA>2.0.CO;2

    Article  Google Scholar 

  • Yeshanew A (2003) Climate variability and prediction in tropical North Africa. Ph.D. thesis, University of Zululand, South Africa, 546 pp

  • C Zhang HH Hendon (1996) ArticleTitlePropagating and standing components of the intra-seasonal oscillation in tropical convection J Atmos Sci 54 741–752 Occurrence Handle10.1175/1520-0469(1997)054<0741:PASCOT>2.0.CO;2

    Article  Google Scholar 

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Authors and Affiliations

  1. Uganda Meteorological Service, Kampala, Uganda

    L. Tazalika

  2. Department of Environmental Studies, University of Zululand, KwaDlangezwa, South Africa

    M. R. Jury

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  1. L. Tazalika
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  2. M. R. Jury
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Correspondence to M. R. Jury.

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Correspondence: Mark R. Jury, Physics Department, University of Puerto Rico, Mayaguez, PR 00681, USA

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Tazalika, L., Jury, M. Intra-seasonal rainfall oscillations over central Africa: space-time character and evolution. Theor Appl Climatol 94, 67–80 (2008). https://doi.org/10.1007/s00704-007-0349-6

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  • DOI: https://doi.org/10.1007/s00704-007-0349-6

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