SAEON expands coastal modelling system for South Africa*

By Charine Collins, Postdoctoral Researcher, SAEON Egagasini Node Tweet

About 60% of the world's population live within 60 km of the coast and it is predicted to rise by 15% within the next 20 years Author Charine Collins is a physical oceanographer with a background in Zoology and Ecology

According to the UN Atlas of the Ocean, about 60% of the world's population live within 60km of the coast and it is predicted to rise by 15% within the next 20 years.

Globally, the coastal zone, accounting for only 7% of the total global ocean landscape, is home to the most biologically diverse and productive ecosystems on Earth. The attractiveness of the coastal zone stems from the extraordinary abundance of natural resources it offers and it also makes the coastal zone a focal point for various human activities.

Despite the importance of the coastal zone, coastal dynamics around South Africa remains shrouded in mystery. The little that is known comes from observational data sets that are scattered in space and time.

Numerical ocean models are valuable tools in overcoming the sparse coverage of observational data. A coastal modelling system can not only be used to improve our understanding of the coastal circulation, it can also be used to predict ocean conditions, monitor and track oil spills, aid with search and rescue operations and so forth.

In 2014, the SAEON Egagasini Node started developing their coastal modelling system for South Africa. The model design is based on a two-tier system.

The first tier, completed by Ben Loveday, consists of a 24.5 km domain spanning the South West Indian Ocean and the South Atlantic Ocean. Nested within this domain is a 7.5 km domain that encompasses the entire coast of South Africa.

Postdoctoral researcher Charine Collins, who started at the Egagasini Node in July 2015, will work on downscaling the coastal zone which makes up the second tier. For Tier 2, two high-resolution (~1km) domains will be nested within the 1/12 domain - one domain will be located on the west coast, and the other will span the south coast and part of the east coast.

These high-resolution coastal simulations will be used to investigate bay-scale circulation dynamics of St Helena Bay, False Bay and Algoa Bay.

* SAEON is collaborating with the Council for Scientific and Industrial Research (CSIR), the University of Cape Town (UCT) and international partners to build the coastal modelling capacity in South Africa.

The coastal modelling system that is being developed for South Africa consists of two tiers - Tier 1 in black and Tier 2 in red

 From honey bees to ocean models

Author Charine Collins is a physical oceanographer with a background in Zoology and Ecology. She started her research endeavours as an honours student looking at the enslavement of the Cape bee (Apis mellifera Capensis) by the African bee (Apis mellifera Scutellata).

Subsequently, Charine entered the Applied Marine Science Master's programme at the University of Cape Town, where her research project focused on long-term trends of Antarctic sea ice. During her master's she became intrigued with the physical processes that govern the ocean and decided to pursue a PhD in Physical Oceanography.

Charine's PhD focused on the dynamics of the Comoros Basin. She used a numerical model as well as observational data to show that the circulation in the Comoros Basin consists of meso-scale eddies instead of a large anti-cyclonic gyre as previously thought