Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Seasonal and interannual variability of wind-driven upwelling at Lüderitz, Namibia
Includes bibliographical references (p. 101-108).
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Department of Oceanography
2014
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613343280267264 |
|---|---|
| access_status_str | Open Access |
| author | Peard, Kathleen Rhona |
| author2 | Shillington, Frank |
| author_browse | Peard, Kathleen Rhona Shillington, Frank |
| author_facet | Shillington, Frank Peard, Kathleen Rhona |
| author_sort | Peard, Kathleen Rhona |
| collection | Thesis |
| description | Includes bibliographical references (p. 101-108). |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/6498 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:34:38.153Z |
| 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:11427/6498 Seasonal and interannual variability of wind-driven upwelling at Lüderitz, Namibia Peard, Kathleen Rhona Shillington, Frank Oceanography Includes bibliographical references (p. 101-108). The aim of this study is to examine the variability in the wind regime at diurnal, seasonal, interannual and interdecadal time scales. Meteorological measurements including wind speed, wind direction and air pressure collected at Dias Point Lighthouse (260 38.094'S 150 05.612'E) at hourly to eight-hourly intervals from 1960 to 2006 are analysed. Known instrument changes in the time series are validated where possible. Predominant winds at Lüderitz blow parallel to the South to North alignment of the coast. Ekman divergence in response to longshore, equatorward wind stress drives coastal upwelling at Lüderitz, the main centre of upwelling in the Benguela Current System. Wind stress is proportional to the square of the wind speed parallel to the coast and is a proxy for upwelling. A diurnal intensification of wind speeds occurred in all seasons at Lüderitz with a concomitant change in wind direction from south in the early morning to southwest in the afternoon. Pressure changes over the continent due to daytime heating and night-time cooling of the land underlie this variability. Southwesterly winds predominate throughout the year at Lüderitz. Maximum wind stress occurs in the austral summer with a fourfold decrease in wind stress during the austral winter. Highest wind stress was recorded from November to January and lowest wind stress from May to July. The wind mixing index, a measure of turbulent mixing calculated from total wind speed cubed, follows the same seasonal pattern indicating the predominance of southerly winds. The wind minimum at Lüderitz is caused by weakened pressure gradients due to the latitudinal northwesterly shift in the position of the South Atlantic Anticyclone in winter combined with a pressure increase over the continent. 2014-08-13T19:52:02Z 2014-08-13T19:52:02Z 2007 Master Thesis Masters MSc http://hdl.handle.net/11427/6498 eng application/pdf Department of Oceanography Faculty of Science University of Cape Town |
| spellingShingle | Oceanography Peard, Kathleen Rhona Seasonal and interannual variability of wind-driven upwelling at Lüderitz, Namibia |
| thesis_degree_str | Master's |
| title | Seasonal and interannual variability of wind-driven upwelling at Lüderitz, Namibia |
| title_full | Seasonal and interannual variability of wind-driven upwelling at Lüderitz, Namibia |
| title_fullStr | Seasonal and interannual variability of wind-driven upwelling at Lüderitz, Namibia |
| title_full_unstemmed | Seasonal and interannual variability of wind-driven upwelling at Lüderitz, Namibia |
| title_short | Seasonal and interannual variability of wind-driven upwelling at Lüderitz, Namibia |
| title_sort | seasonal and interannual variability of wind driven upwelling at luderitz namibia |
| topic | Oceanography |
| url | http://hdl.handle.net/11427/6498 |
| work_keys_str_mv | AT peardkathleenrhona seasonalandinterannualvariabilityofwinddrivenupwellingatluderitznamibia |