Evaluating multi-satellite chlorophyll-a datasets an ocean colour case study within the Southern Benguela

Simple item page
dc.contributor.advisorCSIR, Smith
dc.contributor.advisorCSIR, Whittle
dc.contributor.authorOehley, Craig
dc.date.accessioned2026-01-16T10:02:19Z
dc.date.available2026-01-16T10:02:19Z
dc.date.issued2025
dc.date.updated2026-01-15T11:54:32Z
dc.description.abstractChlorophyll-a (chl-a), a photosynthetic pigment that can be derived from satellite ocean colour, is often used as a proxy for phytoplankton biomass and to derive primary productivity. Initiatives such as the Ocean Colour Climate Change Initiative (OC-CCI) produce merged multi-satellite products to create consistent long-term time-series datasets for climate studies at a global scale. Their ability to handle variable in-water conditions is critical for their mission parameters. This study compares the performance of two European multi-satellite chl-a products, from the OC-CCI and GlobColour projects against a regionally tuned Sentinel-3 product within the Southern Benguela region. The three products were assessed against a collated database of coincident in situ chl-a matchups to derive a series of performance metrics. The regionally tuned Sentinel-3 product outperformed the two global products in terms of Mean Absolute Error but showed a slight consistent overestimation bias. Analysis of match-ups showed an underestimation of high chl-a concentrations and overestimation of lower chl-a concentrations by both global products. An application of the products within St.Helena bay during high biomass bloom events showed that the Sentinel-3 product's ability to capture extreme chl-a concentrations was far higher than both global products. Spatial mismatch between zones of high chl-a concentration also indicate differences in processing chains and flagging techniques.
dc.identifier.apacitationOehley, C. (2025). <i>Evaluating multi-satellite chlorophyll-a datasets an ocean colour case study within the Southern Benguela</i>. (). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/42589en_ZA
dc.identifier.chicagocitationOehley, Craig. <i>"Evaluating multi-satellite chlorophyll-a datasets an ocean colour case study within the Southern Benguela."</i> ., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2025. http://hdl.handle.net/11427/42589en_ZA
dc.identifier.citationOehley, C. 2025. Evaluating multi-satellite chlorophyll-a datasets an ocean colour case study within the Southern Benguela. . University of Cape Town ,Faculty of Science ,Department of Biological Sciences. http://hdl.handle.net/11427/42589en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Oehley, Craig AB - Chlorophyll-a (chl-a), a photosynthetic pigment that can be derived from satellite ocean colour, is often used as a proxy for phytoplankton biomass and to derive primary productivity. Initiatives such as the Ocean Colour Climate Change Initiative (OC-CCI) produce merged multi-satellite products to create consistent long-term time-series datasets for climate studies at a global scale. Their ability to handle variable in-water conditions is critical for their mission parameters. This study compares the performance of two European multi-satellite chl-a products, from the OC-CCI and GlobColour projects against a regionally tuned Sentinel-3 product within the Southern Benguela region. The three products were assessed against a collated database of coincident in situ chl-a matchups to derive a series of performance metrics. The regionally tuned Sentinel-3 product outperformed the two global products in terms of Mean Absolute Error but showed a slight consistent overestimation bias. Analysis of match-ups showed an underestimation of high chl-a concentrations and overestimation of lower chl-a concentrations by both global products. An application of the products within St.Helena bay during high biomass bloom events showed that the Sentinel-3 product's ability to capture extreme chl-a concentrations was far higher than both global products. Spatial mismatch between zones of high chl-a concentration also indicate differences in processing chains and flagging techniques. DA - 2025 DB - OpenUCT DP - University of Cape Town KW - Ocean colour KW - Southern Benguela LK - https://open.uct.ac.za PB - University of Cape Town PY - 2025 T1 - Evaluating multi-satellite chlorophyll-a datasets an ocean colour case study within the Southern Benguela TI - Evaluating multi-satellite chlorophyll-a datasets an ocean colour case study within the Southern Benguela UR - http://hdl.handle.net/11427/42589 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/42589
dc.identifier.vancouvercitationOehley C. Evaluating multi-satellite chlorophyll-a datasets an ocean colour case study within the Southern Benguela. []. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2025 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/42589en_ZA
dc.language.isoen
dc.language.rfc3066eng
dc.publisher.departmentDepartment of Biological Sciences
dc.publisher.facultyFaculty of Science
dc.publisher.institutionUniversity of Cape Town
dc.subjectOcean colour
dc.subjectSouthern Benguela
dc.titleEvaluating multi-satellite chlorophyll-a datasets an ocean colour case study within the Southern Benguela
dc.typeThesis / Dissertation
dc.type.qualificationlevelMasters
dc.type.qualificationlevelMSc
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
thesis_sci_2025_oehley craig.pdf
Size:
6.02 MB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.72 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Masters