Seasonal and intra-seasonal dynamics and precursors of rainfall over northern Tanzania

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dc.contributor.advisorJury, Mark Ren_ZA
dc.contributor.authorKabanda, Tibangayuka Abbasen_ZA
dc.date.accessioned2016-08-24T12:59:45Z
dc.date.available2016-08-24T12:59:45Z
dc.date.issued1995en_ZA
dc.description.abstractThe structure and variability of inter-annual and intra-seasonal circulation anomalies and their precursors are investigated over northern Tanzania. Area rainfall departures are computed in the period 1960-1990 and wet and dry years are identified. Northern Tanzania experiences bimodal rains centred on the seasons: March to May (Masika) and October to December (Vuli). Station inter-correlations in Masika are of order +0.4, whereas in Vuli correlations are of order+0.7. Using composite sequences of gridded sea surface temperatures (SST),outgoing longwave radiation (OLR) and winds in the lower- and upper troposphere, the- precursors of flood and drought are assessed. Composites are averaged for the specific season and for periods 2, 4 and 6 months prior; and the historical mean is subtracted to produce anomalies. In this way, evolution of extreme rainfall scenarios is tracked for predictive purposes. The patterns analysed show that when positive SST anomalies persist in the Indian Ocean, sympathetic negative OLR values and local rainfall enhancement are observed. Using pentad (5 day mean) rainfall time series for the area, wet spells are analysed for structure and evolution. ECMWF data for the peak in Vuli rainfall each year from 1986 to 1991 are averaged to form a single composite. The historical mean is subtracted from the composite to produce anomalies for the wet spell and the preceeding pentads.en_ZA
dc.identifier.apacitationKabanda, T. A. (1995). <i>Seasonal and intra-seasonal dynamics and precursors of rainfall over northern Tanzania</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Oceanography. Retrieved from http://hdl.handle.net/11427/21513en_ZA
dc.identifier.chicagocitationKabanda, Tibangayuka Abbas. <i>"Seasonal and intra-seasonal dynamics and precursors of rainfall over northern Tanzania."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Oceanography, 1995. http://hdl.handle.net/11427/21513en_ZA
dc.identifier.citationKabanda, T. 1995. Seasonal and intra-seasonal dynamics and precursors of rainfall over northern Tanzania. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Kabanda, Tibangayuka Abbas AB - The structure and variability of inter-annual and intra-seasonal circulation anomalies and their precursors are investigated over northern Tanzania. Area rainfall departures are computed in the period 1960-1990 and wet and dry years are identified. Northern Tanzania experiences bimodal rains centred on the seasons: March to May (Masika) and October to December (Vuli). Station inter-correlations in Masika are of order +0.4, whereas in Vuli correlations are of order+0.7. Using composite sequences of gridded sea surface temperatures (SST),outgoing longwave radiation (OLR) and winds in the lower- and upper troposphere, the- precursors of flood and drought are assessed. Composites are averaged for the specific season and for periods 2, 4 and 6 months prior; and the historical mean is subtracted to produce anomalies. In this way, evolution of extreme rainfall scenarios is tracked for predictive purposes. The patterns analysed show that when positive SST anomalies persist in the Indian Ocean, sympathetic negative OLR values and local rainfall enhancement are observed. Using pentad (5 day mean) rainfall time series for the area, wet spells are analysed for structure and evolution. ECMWF data for the peak in Vuli rainfall each year from 1986 to 1991 are averaged to form a single composite. The historical mean is subtracted from the composite to produce anomalies for the wet spell and the preceeding pentads. DA - 1995 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1995 T1 - Seasonal and intra-seasonal dynamics and precursors of rainfall over northern Tanzania TI - Seasonal and intra-seasonal dynamics and precursors of rainfall over northern Tanzania UR - http://hdl.handle.net/11427/21513 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/21513
dc.identifier.vancouvercitationKabanda TA. Seasonal and intra-seasonal dynamics and precursors of rainfall over northern Tanzania. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Oceanography, 1995 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/21513en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Oceanographyen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherOceanographyen_ZA
dc.titleSeasonal and intra-seasonal dynamics and precursors of rainfall over northern Tanzaniaen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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