A combination of satellite and in situ data were used to infer the occurrence and temporalspatial variability of upwelling near Angoche. The data were derived from MODIS SST and Chl-a between 2003 and 2007, in situ moored underwater temperature recorder at a depth of 18 m for the period 2003ô2007 and two shipboard surveys providing CTD and XBT data in December 2008 and in August 2009 in the northern Mozambique region. The results con rm that shelf edge upwelling occurs along the northern coast of Mozambique near Angoche between 15 and 18oS, covering an area of approximately 68 000 km2. The upwelling signature was not strong at the surface. Two upwelling core regions were identi ed: (1) the shelf core region and (2) the slope core region. At the shelf core region upwelling was more persistent than at the slope core upwelling. The upwelling displayed seasonal variation between persistent downwelling (warm water) between AprilôJuly and intermittent upwelling (cool water) events between AugustôMarch. Generally the upwelling lasted for a period of about two months but, shorter periods between 8 and 30 days were also observed. The driving mechanism for the shelf edge upwelling o northern Mozambique was determined from satellite observations (NOAA/NCDC) of blended sea surface wind data, and by multi-satellite (AVISO) altimeter sea surface anomaly data between 2003 and 2007 and also during the two cruise surveys in December 2008 and August 2009. These data showed upwelling is in part wind-driven in response to the northôeasterly (NE) monsoon weak-wind velocities between AugustôMarch in the austral spring-summer. The intermittent nature of the upwelling season is also partly due to uctuations in wind direction during the NE monsoon winds. Eddies appear to play a limited role in driving the upwelling.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uct/oai:localhost:11427/6127 |
| Date | January 2010 |
| Creators | Malauene, Bernardino Sergio |
| Contributors | Shillington, Frank, Moloney, Coleen, Roberts, Mike |
| Publisher | University of Cape Town, Faculty of Science, Department of Biological Sciences |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Master Thesis, Masters, MSc |
| Format | application/pdf |
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