Thesis (MSc)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The oceanic and meteorological systems that characterize the southern African coastline are
well-documented. In this thesis, these characteristics have been considered in conjunction with
the analysis of a unique set of sea surface temperature (SST) data, obtained from measuring
sites around the southern African coast, to determine the variability of SSTs in the immediate
coastal region of southern Africa, and to demonstrate how this variability impacts on marinerelated
economic activities. As part of the analysis process, various statistical techniques have
been applied to the data over different time periods to establish the extent of the spatial
variability of SSTs along the southern African coastline.
From the results it has been possible to identify three distinctly different 'climatological' regions
around the southern African coast; viz a cooler west coast region with a low annual and
seasonal SST variability and a higher variability from day-ta-day, a warmer east coast region
with a higher annual and seasonal SST variability and a lower variability from day-ta-day; and a
temperate south coast region with a highly erratic annual, seasonal and day-ta-day SST
variability. Furthermore, it has been possible to identify, albeit small, the existence of a high and
a low frequency signal of 12-15 days and 40-60 days, respectively, in the three different regions.
There is also evidence of the periodic occurrence of anomalously warm and cold SST events in
all three regions, and a probability of <1.1% of a day-ta-day SST anomaly of >3°C (+3°C or-
3°C) occurring anywhere along the southern African coastline.
The general causes of SST change have been discussed within the context of the heat budget
equation. Furthermore, the effects of the variability of SST on the climate and marine life around
southern Africa and the resulting impact on the various marine-related economic activities (such
as aquaculture, air-sea rescue and power stations) have been identified, and shown to be both
positive and negative.Finally, it should be noted, that economic infonnation relating to marine activities is closely
guarded due to inter-industry competition. It has therefore been difficult to quantify the exact
impact of the effects of SST variability on these activities. / AFRIKAANSE OPSOMMING: Die oseaniese en weerkundige stelsels wat die kuslyn van suidelike Afrika kenmerk is goed
gedokumenteer. Die stelselkenmerke is in hierdie verhandeling ondersoek aan die hand van 'n
unieke datastel van seeoppervlaktemperature (SST) afkomstig van meetplekke aan die kus van
suidelike Afrika, ten einde die veranderlikheid van SST in die onmiddelike kusomgewing van
suidelike Afrika vas te stel, asook om te demonstreer hoe hierdie veranderlikheid inwerk op seeverwante
ekonomiese aktiwiteite. As deel van die proses van analise is verskeie statistiese
metodes gebruik om die data oor verskeie tydperke te ontleed ten einde die omvang van
ruimtelike veranderlikheid van SSTs langs die kus van suidelike Afrika te bepaal.
Uit die resultate was dit moontlik om drie duidelike onderskeibare 'klimatologiese' streke aan die
kus van suidelike Afrika te identifiseer; te wete 'n koeler weskusstreek met 'n lae jaarlikse en
seisoenale SST-veranderlikheid en hoër dag-tot-dag veranderlikheid, 'n warmer ooskusstreek
met 'n hoër jaarlikse en seisoenale SST-veranderlikheid en laer dag-tot-dag verandelikheid;
asook 'n gematigde suidkusstreek met 'n hoogs wisselvallige jaarlikse, seisoenale en dag-totdag
SST-veranderlikheid. Dit was verder moontlik om, alhoewel klein, die bestaan van lae en
hoë frekwensie seine van 12-15 dae en 40-60 dae onderskeidelik in die drie streke te
identifiseer. Daar is ook tekens van die periodieke voorkoms van anomale warm en koue SSTgebeurtenisse
in al drie streke en 'n waarskynlikheid van <1.1% van die voorkoms van 'n dagtot-
dag SST-anomaliteit van >3°C (+3°C of -3°G) op enige plek langs die suider Afrikaanse
kuslyn.
Die algemene oorsake van veranderings in SST is bespreek binne die konteks van die formule
vir die behoud van hitte-energie. Die invloed van SST-veranderlikheid op die klimaat en die
seelewe om suidelike Afrika en die gevolglike effek op mariene-verwante ekonomiese aktiwiteite (soos akwakultuur, lug-see-redding en kragstasies) is ook geïdentifiseer en is aangetoon om
beide positief en negatief te wees
Ten laaste dien dit gemeld te word dat ekonomiese inligting met betrekking tot mariene
aktiwitweite goed bewaar word as gevolg van kompetisie in die bedryf. Dit was derhalwe
moeilik om die presiese impak van die gevolge van SST-veranderlikheid op sodanige aktiwiteite
te kwantifiseer.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/53583 |
| Date | 04 1900 |
| Creators | Greenwood, Karin C. |
| Contributors | Grundlingh, L., Schloms, B., Stellenbosch University. Faculty of Arts and Social Sciences. Dept. of Geography and Environmental Studies . |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 1 v. (various pagings) : ill. |
| Rights | Stellenbosch University |
Page generated in 0.0027 seconds