Cross shelf dynamics in the Agulhas Current region from GlobCurrent and glider observations

Tumelo Maja
Nansen-Tutu, University of Cape Town, South Africa and Council for Scientific and Industrial Research
Seminar Date: 
27. September 2018 - 12:30 - 13:00
Lecture room, Ground Floor, NERSC

The Agulhas Current is the strongest western boundary current in the southern hemisphere and a major driver of variability for coastal regions along South Africa’s eastern shores. Interactions between the Agulhas Current and the steep and narrow continental shelf drive a range of instabilities at the meso (50 – 200 km) and sub-meso (<10 km) scales, such as the shedding of eddies, plumes and filaments, as well as the meandering or intrusion of the current onto the shelf (Krug et al., 2017). Accurate observations are required to understand how changes in the Agulhas Current are impacting the neighbouring coastal regions. We use in-situ observations of ocean currents collected from gliders, Shelf in the Agulhas Glider Experiment (SAGE : April-May 2015) and the Glider in the Agulhas (GINA : June-August 2017) experiment, to assess the ability of the GlobCurrent product to capture both meso and sub-mesoscale ocean processes in the Agulhas Current’s shelf regions. We present the along- and cross-shelf comparisons of currents from Globcurrent and Seagliders. High resolution SST satellite products are used to describe meso and submesoscale structures and their evolution along the coast of South Africa. The findings will guide future improvements to the GlobCurrent product and improve our ability to monitor the Agulhas Current and its impact on the coastal regions

Prof Mathieu Rouault - UCT
Dr Marjolaine Krug - CSIR
Dr Johnny Johannessen - NERSC