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Numerical simulation of a mesoscale convective system over the east coast of South Africa
Includes bibliographical references (leaves 189-200).
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| Main Author: | |
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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Department of Oceanography
2014
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| _version_ | 1867613166349844481 |
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| access_status_str | Open Access |
| author | Blamey, Ross |
| author2 | Reason, Chris |
| author_browse | Blamey, Ross Reason, Chris |
| author_facet | Reason, Chris Blamey, Ross |
| author_sort | Blamey, Ross |
| collection | Thesis |
| description | Includes bibliographical references (leaves 189-200). |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/6463 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:31:48.735Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2014 |
| publishDateRange | 2014 |
| publishDateSort | 2014 |
| publisher | Department of Oceanography |
| publisherStr | Department of Oceanography |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/6463 Numerical simulation of a mesoscale convective system over the east coast of South Africa Blamey, Ross Reason, Chris Oceanography Includes bibliographical references (leaves 189-200). Weather stations across the northern KwaZulu-Natal coastline recorded over 100 mm of rainfall over the 11112 February 2005, with Cape St. Lucia and Richards Bay measuring 111 mm and 96.8 mm, respectively. This heavy rainfall was associated with a mesoscale convective system (MCS) that initiated through small convective storms beginning early in the afternoon on 11 February 2005 and eventually decayed in the early morning hours on the 12th. The high-lying topography of the eastern escarpment and high diurnal surface heating possibly provided the trigger for the event. It was also identified that a combination of synoptic features in and around South Africa contributed to the evolution of the system. This particular MCS is investigated with a non-hydrostatic numerical model (MM5) to help determine which processes were important in its initiation and development, as well as what factors contributed to the associated heavy rainfall. The model is also used to conduct sensitivity tests to determine the role that local features, such as the regional topography and sea surface temperature, played in the evolution of the system. Through the various MM5 simulations, it was evident that the eastern escarpment played a key role in triggering the convective event, while it also had an influence on the low level winds that advected moisture into the region. A sea surface temperature sensitivity simulation highlighted the important role that the Agulhas Current plays in supplying moisture to fuel extreme precipitation events in South Africa. The significance of resolving large-scale features in the mid-latitudes in numerical simulations of weather events in South Africa was identified when excluding these features from the simulation. Through these simulations it was identified that the development of the MCS and the heavy nocturnal precipitation was due to a combination of the continuous moisture supply into the region, a conditionally unstable atmosphere, and uplift due to low level convergence and the local topography. 2014-08-13T19:48:25Z 2014-08-13T19:48:25Z 2007 Master Thesis Masters MSc http://hdl.handle.net/11427/6463 eng application/pdf Department of Oceanography Faculty of Science University of Cape Town |
| spellingShingle | Oceanography Blamey, Ross Numerical simulation of a mesoscale convective system over the east coast of South Africa |
| thesis_degree_str | Master's |
| title | Numerical simulation of a mesoscale convective system over the east coast of South Africa |
| title_full | Numerical simulation of a mesoscale convective system over the east coast of South Africa |
| title_fullStr | Numerical simulation of a mesoscale convective system over the east coast of South Africa |
| title_full_unstemmed | Numerical simulation of a mesoscale convective system over the east coast of South Africa |
| title_short | Numerical simulation of a mesoscale convective system over the east coast of South Africa |
| title_sort | numerical simulation of a mesoscale convective system over the east coast of south africa |
| topic | Oceanography |
| url | http://hdl.handle.net/11427/6463 |
| work_keys_str_mv | AT blameyross numericalsimulationofamesoscaleconvectivesystemovertheeastcoastofsouthafrica |