- Title
- An Investigation of the variability of oceanic turbulence in the Agulhas Current: focus on the Durban Eddies and Natal Pulses
- Creator
- Burgher, Nasreen
- Subject
- Ocean currents -- Indian Ocean
- Subject
- Oceanography
- Subject
- Genetic algorithms
- Date Issued
- 2023-04
- Date
- 2023-04
- Type
- Master's theses
- Type
- text
- Identifier
- http://hdl.handle.net/10948/69530
- Identifier
- vital:77276
- Description
- Coastal-ocean waters inshore of the Agulhas Current (AC) are largely affected by oceanic (sub-)mesoscale turbulence. These events are generally in the form of meanders, such as AC cyclonic meanders (Natal Pulses and Durban Eddies), and have been observed to play a role in shelf upwelling. Using several high-resolution sea surface temperature (SST) satellite products, the turbulent inshore region of the AC was investigated by means of an automated algorithm designed to identify thermal gradients along cross-shore transects. These features are associated with strong SST gradients which are better represented in higher-resolution products. Results yielded high amounts of variability in the regions south of 33.7°S and north of 32.2°S. Four types of inshore boundary features were identified from the variability, which are Natal Pulses, Durban Eddies, upwelling and the fourth was identified as a frontal change. In the Level 4 (L4) SST dataset, the algorithm resulted in 0.46 occurrences of Natal Pulses per year Manual detection resulted in 1.4 events per year. The DE occurred more regularly and was observed spawning at 30°S every one to three weeks in the Level 2 (L2) datasets. Both the L2 and L4 datasets revealed similar characteristics of Natal Pulses and Durban Eddies based on three case studies. Lastly, the RESILIENCE cruise case study compared SST thermosalinograph data to the L2 and L4 SST products and found that the L2 product had better agreement with the in situ data compared to the L4 product.
- Description
- Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
- Format
- computer
- Format
- online resource
- Format
- application/pdf
- Format
- 1 online resource (93 pages)
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
- Rights
- All Rights Reserved
- Rights
- Open Access
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Burgher, N.pdf | 2 MB | Adobe Acrobat PDF | View Details Download |