First Chapman Conference held in Africa - On the Agulhas current system and its role in changing ocean circulation, climate and marine ecosystems

"The Chapman Conference showcased South Africa as an important research destination and highlighted the increasingly important role of SAEON as an emerging NRF facility." - Dr Juliet Hermes, Manager, SAEON Egagasini Node In his opening address Dr Gansen Pillay, Deputy CEO of the NRF challenged the delegates to "think beyond the discipline" of natural science to hone its relevance to the social sciences. Dr Lisa Beal spoke about how the Agulhas leakage modulates climate. She said there is a big need for much more research to be done into this important field. South Africa plays a vital role in observing this meridional overturning circulation.

Dr Juliet Hermes, Manager of SAEON’s Egagasini Node for marine offshore systems, acted as local convener of the first American Geophysical Union Chapman Conference to be held on the African Continent and the first dedicated Agulhas conference ever.

The initiative was driven by the SCOR (Scientific Committee on Oceanic Research) IAPSO (International Association for the Physical Sciences of the Oceans) working group 136, of which Dr Hermes is a member.

The conference brought together scientists from around the world to present their research, exchange ideas and collectively advance our understanding of the Agulhas Current system from an interdisciplinary perspective, and this was most definitely achieved.

Over 100 delegates and around 30 students attended the conference, the majority of whom were international, representing more than 10 nations.

Addressing the most pressing questions

The purpose of the conference was to identify the most pressing questions around the Agulhas Current system and to design modelling experiments in combination with paleo-ceanographic and (sustained) modern observations to establish the role of the Agulhas system from regional to global scales.

Important objectives were to enhance and facilitate new scientific interactions and collaborations between scientists, institutions and countries interested in and/or actively investigating the greater Agulhas system and its interactions with the atmosphere and marine ecosystems. An implementation plan for an observing system in the southwest Indian Ocean was developed under the auspices of the Global Ocean Observing System.

Conference programme

The programme consisted of an exciting mix of oral presentations, posters, group discussions, social events and field trips. The agenda covered a wide range of topics, including physical oceanography, meteorology, climate, paleo studies, marine ecosystems, fisheries and biogeochemical cycles.

Topics related to air-sea interaction and climate change and perspectives ranged from regional to global scales, attesting to the importance of the Agulhas Current as a key element of the general ocean circulation.

The conference was structured into four main thematic sessions, each related to a leading scientific question:

• What are the main circulation and transport features of the greater Agulhas System?
• What are the effects of Agulhas system variability on regional weather, climate, bio-physical interactions, marine ecosystems and fisheries?
• What is the impact of Agulhas Retroflection and Leakage on large-scale ocean circulation and climate?
• What are the physical mechanisms that link the Agulhas system to changes in ocean circulation and climate?

Societal impacts

"How do we care for the ocean in a way that meaningfully impacts on people?" This was the question posed by Dr Gansen Pillay, Deputy CEO of the National Research Foundation (NRF) in his opening address, highlighting not only the need to develop human capacity in this area but also to fully understand the impact of the region on social development. He challenged the delegates to "think beyond the discipline" of natural science to hone its relevance to the social sciences.

The morning discussion sessions (as well as discussion sessions after each morning’s talks) provided insight into future ideas and plans, in particular with regard to numerical modelling, observations and implementation.

An outcome of this was that both Dr Lisa Beal (Associate Professor, Meteorology and Physical Oceanography at the University of Miami) and Dr Herman Ridderinkof (Deputy Director: Royal Netherlands Institute for Sea Research) have offered that the millions of dollars worth of equipment which is currently in place in the Agulhas Current (off East London) and the Mozambique Channel be ‘given’ to South Africa if we are able to maintain the mooring arrays and if the data are made freely available.

"This is an incredible opportunity which we need to grasp," Dr Hermes said.

On Wednesday afternoon, the Education Outreach Officer of the SAEON Egagasini Node, Thomas Mtontsi took some of the international scientists on a visit to the Egagasini schools in the region that form part of the SAEON Egagasini Node’s education outreach programme. Thomas was able to use this time to further develop collaborations around the adopt-a-drifter programme.

SAEON’s key role in long-term monitoring

"The American Geophysical Union Chapman Conference showcased South Africa as an important research destination and highlighted the increasingly important role of SAEON as an emerging NRF facility," Dr Hermes said.

SAEON was noted as a key organisation in terms of long- term monitoring, data and capacity building. Specific mention was made of the potential support SAEON could offer in terms of long-term monitoring in the Agulhas region.

Positive outcomes

The conference provided an excellent platform for all young, early career and established researchers working in the Agulhas region to interact and strengthen international, regional and national networks.

Further collaborations were instigated during the conference, in particular regarding the French IRD (Institute of Research for Development) and the marine laboratory they will be setting up in South Africa; the US Office of Naval Research and future work off the Agulhas bank; NOAA (National Oceanic and Atmospheric Administration) and future drifter studies in the Agulhas region, both through education and student opportunities; the future of the NSF (National Science Foundation) funded Agulhas Current Array; a potential PEER (Public Employees for Environmental Responsibility) proposal.

The organisers received only positive comments about the layout, local organisation and content of the meeting. Comments from delegates included the following:

"I enjoyed the Chapman Conference and it was one of the best meetings that I have ever attended. My colleagues from Japan also told me the same. Thank you for all of your efforts and time in preparing for the conference!"

"It was the best conference I have ever experienced. We must not lose the momentum."

For further information, contact Dr Juliet Hermes

Currents around South Africa

Currents around South Africa (snapshot). The Agulhas Current (red band) flows along the South African coast. South-west of Cape Town it abruptly turns back into the Indian Ocean. In this process huge rings of water are cut off that flow westward into the Atlantic Ocean. (The colours indicate the strength of the currents.) (Credit: Image courtesy of Leibniz Institute of Marine Sciences)

Agulhas current and leakage

This figure shows the Agulhas system and its leakage into the South Atlantic. The southward shift of the winds in a warming climate (right panel) cause a southward shift of the subtropical front (red arrows), enlarging the "gateway" for Agulhas leakage around the tip of Africa. Increased Agulhas leakage acts to enhance Atlantic overturning, which causes a feedback on climate. (Background colors are dynamic height integrated between 2000 m and the surface). Credit: Erik van Sebille, UM/RSMAS