Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 12 of 12 for “"Cut-off lows"”.
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Dynamical processes in the evolution of Cut Off Lows over South Africa
… study presented deviations in the evolution of Cut-off lows (COLs) through four COLs events over the South African domain from a case study point of view. Furthermore, this study demonstrated COLs as cold-cored low-pressure systems estranged from westerly wind belts above . COLs are hazardous as …
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Understanding the characteristics of cut-off lows over the Western Cape, South Africa
Cut-off lows (COLs) are an important rainfall source in the Western Cape. While several studies have examined the devastating impacts of COLs during extreme rainfall events, little is known about the characteristics of COLs during droughts and how the characteristics are influenced by the South …
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Characteristics of deep moist convection and rainfall in cut-off lows over South Africa
Out of all rain-producing weather systems, cut-off lows (COLs) are linked with the occurrence of high impact rainfall and in some cases short-lived floods which can last for 24 hours over South Africa. This study examined the characteristics associated with the present occurrence of the severe COL …
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Cut-off low pressure systems and extreme rainfall over South Africa
This thesis is an investigation of cut-off low pressure systems over South Africa. These weather systems have been responsible for many of the flooding disasters that have affected South Africa, particularly the coastal regions, over recent decades. The thesis has two main objectives, namely, to …
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An examination of changes in rainfall, streamflow and landcover a case study of the Kandelaars catchment, Oudtshoorn, South Africa 1926 to 2008
… conditions, most notably in the form of cut-off lows, which have been projected to intensify with the changing climate.
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Variability and long-term trends of climate extremes over the Limpopo, South Africa
… latitudinal location and low altitude. Anomalous cut-off lows, tropical cyclones and tropical storms are the major extreme producing systems affecting the Limpopo province whilst the Botswana High becomes dominant during heat waves and drought. Extreme weather events are common in Limpopo during …
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Extreme rainfall events over the Pongola-Mtamvuna Water Management Area of South Africa
… rainfall events were associated with tropical lows (40%) and MCS (20%). Cut-off lows (18%), cloud bands (16%), and tropical cyclones (6%) contributed to the remaining proportion. The highest frequency of events occurred during late summer months (January – March) when tropical lows and …
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Impact of spatio-temporal variability of the Mascarene High on weather and climate over Southern Africa
… Africa associated with tropical cyclones, cut-off lows and cloud bands. There is also a vital geographical variability of the Mascarene High development, distribution and movement in the South Indian Ocean at the different time-scales. Projections of the Mascarene High indicate a shift in …
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The synoptic drivers of extreme rainfall in South Africa
… amount of extreme rainfall events such as cut-off lows in the south-western parts of the country were poorly characterized by the regional SOMs. This may be attributed to the spatial boundaries adopted in this study and suggests general rainfall regimes developed for South Africa are not …
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An analysis of heavy rainfall events over the Limpopo River Basin in southern Africa, their moisture sources and pathways
… for almost half of the events and tropical lows are responsible for just over a quarter. The remaining quarter of the events are associated with mesoscale convective systems and cut-off lows, the latter more important during transition seasons. Most of the events occur in the late summer …
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An analysis of anomalously wet summers in the South Western Cape of South Africa
… to be linked to atmospheric rivers (ARs) or cut-off lows (COLs), which together account for up to 88% of the top 75 LREs. Apart from one study characterising the considerable effect of ARs on winter rainfall, to date little research on ARs has been done for the region. Furthermore, COLs have …
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Long-lived mesoscale convective systems over Eastern South Africa
… often focused on synoptic-scale systems such as cut off lows, tropical extratropical cloud bands, and tropical cyclones, with little attention placed on the smaller mesoscale convective systems (MCSs). On a global scale, MCSs are not only important as key rainfall producers, but are often …