Coastal Operations at Sea Decision Support Tool

South Africa’s Exclusive Economic Zone (EEZ) encompasses the coastal ocean and shelf sea waters. The region is characterised by one of the world’s most  energetic and productive ocean systems, namely the Agulhas Current and Benguela Upwelling System. Both play fundamental roles in the marine environment, its resources and ecosystem and the regional weather and global climate.

Our ability to predict the ocean and sea state surrounding southern Africa represents a direct benefit to the industrial, commercial and leisure activities, including the monitoring of accidental pollutants, such as oil spills as well as harmful algal blooms.

The Coastal Operations at Sea (CoastOps) Decision Support Tool (DeST) provides a capability for monitoring and predicting ocean and sea state variables in the coastal ocean using state-of-art forecasts of winds, currents and waves, which are provided by numerical models that simulate and predict ocean and atmospheric conditions. Ocean and atmosphere general circulation models are complex mathematical models, that use the Navier-Stokes equations on a rotating sphere as the basis for computer programs to simulate the Earth’s atmosphere or oceans on a range of spatio-temporal scales. Similarly, wave models simulate the sea state and predict its evolution using numerical techniques taking into consideration atmospheric wind forcing, non-linear wave interaction and frictional dissipation. In an integrated and coupled approach these modelling systems provide the ocean current, wave and wind forecasts used in the DeST.

The Delft3D Flexible Mesh Suite for modelling the coastal ocean, estuaries and rivers is used here providing ocean and sea state forecasts for the coastal ocean for key port cities, including:

  • False and Table Bay (under development)
  • Saldanha and St Helena Bay (under development)
  • Algoa Bay (under development)

Using these ocean state and wind forecasts, the CoastOps DeST provides support for the search and rescue operations of the National Sea Rescue Institute (NSRI). The NSRI is a voluntary non-profit organisation that works closely with other search and rescue organisations in South Africa, including the South African Maritime Safety Authority (SAMSA), its Maritime Rescue Coordination Center, the South African Navy, the Air Force and the South African Red Cross Air Mercy Service, and is tasked with saving lives on South African waters.

The NSRI relies on a variety of tools and data streams to coordinate their search and rescue operations, none of them optimally tailored to their operational needs. Here, the CoastOps DeST provides a web-based utility that integrates all the necessary information into a digital virtual command center to improve NSRI’s ability to coordinate and respond to search and rescue calls.

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