“South African scientists have joined an Antarctic Saildrone research mission using autonomous sailing vehicles to investigate how the Southern Ocean absorbs carbon dioxide and excess heat from the atmosphere. The mission is expected to improve scientific understanding of ocean-driven climate regulation, strengthen climate forecasting and provide valuable observations of one of the planet’s most important but difficult-to-study environmental systems.”
Robotic Sailors Take on Antarctica’s Winter Storms as South African Scientists Investigate Ocean Carbon Absorption
South African scientists are participating in an ambitious international scientific mission using autonomous sailing drones to investigate one of the planet’s most important climate-regulating systems: the Southern Ocean surrounding Antarctica. The research, which began with the deployment of an uncrewed ocean vessel in September 2026, aims to improve understanding of how oceans absorb carbon dioxide and excess heat from the atmosphere, particularly during the harsh Antarctic winter.
The project represents an important development in environmental science and technology, combining autonomous maritime systems, satellite communication, advanced oceanographic instruments and machine learning to address major uncertainties in global climate research.
According to the Mail & Guardian, the international mission involves researchers from South Africa, Australia and the United States. Four autonomous sailing vessels are expected to circumnavigate Antarctica, collecting environmental observations in waters where traditional research ships face significant operational challenges.
Southern Ocean: A Critical Climate Regulator
The Southern Ocean is one of the most influential components of Earth’s climate system. Encircling Antarctica, it absorbs substantial quantities of atmospheric carbon dioxide while taking up considerable amounts of excess heat generated by greenhouse gases.
Scientists estimate that the Southern Ocean accounts for approximately 40% of the global ocean’s carbon dioxide uptake and absorbs around 75% of the excess heat associated with carbon dioxide remaining in the atmosphere.
These functions make the region essential to understanding how the planet responds to rising greenhouse gas concentrations.
However, despite its significance, researchers still face considerable uncertainty about precisely how much carbon dioxide the Southern Ocean absorbs and how these processes change throughout the year.
Dr Sandy Thomalla, a chief researcher at South Africa’s Council for Scientific and Industrial Research (CSIR) and head of its Southern Ocean Carbon-Climate Observatory (SOCCO), has emphasised the importance of investigating the ocean’s climate-buffering capabilities.
The Southern Ocean’s capacity to absorb carbon dioxide cannot be assumed to remain constant. Climate change, shifting ocean circulation, changing temperatures and variations in wind patterns could influence how effectively the region continues to regulate atmospheric carbon.
Consequently, improved observations are essential for determining whether the ocean’s carbon absorption capacity is changing and what those changes could mean for future global warming.
Winter Observations Address a Major Scientific Gap
One of the central objectives of the Antarctic research mission is to address a significant shortage of wintertime observations.
Most scientific expeditions to the Southern Ocean take place during summer, when temperatures are relatively manageable and sea conditions are generally more suitable for research vessels.
During winter, however, the region experiences extreme cold, powerful storms, extensive sea ice and dangerous maritime conditions.
These challenges limit the ability of conventional research ships to collect continuous measurements, leaving scientists with substantial gaps in their understanding of winter ocean processes.
Dr Sarah Nicholson, a lead oceanographer at CSIR’s SOCCO, has described wintertime observations as a major weakness in existing scientific knowledge.
Researchers suspect that winter conditions may contribute significantly to uncertainty surrounding the global ocean carbon sink.
Without reliable measurements during this period, scientists cannot accurately determine how seasonal variations influence carbon dioxide exchanges between the atmosphere and the ocean.
The new autonomous mission therefore seeks to provide observations during precisely the conditions when conventional scientific expeditions struggle to operate.
Autonomous Sailing Technology Enters Antarctic Research
The mission uses Saildrone autonomous surface vehicles designed to navigate challenging ocean environments while collecting scientific measurements.
The first vessel was launched from Bruny Island near Hobart, Tasmania, on 20 September 2026.
It is expected to travel more than 22,000 kilometres while measuring carbon dioxide exchanges between the atmosphere and ocean.
Additional measurements include ocean temperature, salinity, wind conditions and other atmospheric and oceanographic variables.
Unlike conventional research vessels, the autonomous platforms operate without onboard crews.
Their propulsion relies primarily on wind, while solar panels supply electricity to scientific instruments and onboard systems.
Researchers can communicate with the vessels through satellite connections and remotely adjust their routes when necessary.
The technology allows scientists to gather observations from remote locations without exposing research crews to dangerous Antarctic winter conditions.
Nevertheless, the Southern Ocean remains an extremely challenging operating environment.
The vessels must withstand powerful winds, severe storms, drifting icebergs and changing sea-ice conditions.
Their rigid sails have been designed to tolerate exceptionally strong winds, including hurricane-force conditions that can occur in the region.
Even with these technological capabilities, researchers acknowledge that autonomous platforms remain vulnerable to environmental hazards.
Previous missions have experienced losses involving similar ocean drones, demonstrating the risks associated with operating scientific equipment in extreme maritime conditions.
Satellite observations of sea ice and iceberg movements will therefore play an important role in navigation and risk management.
Machine Learning and Climate Modelling
The Antarctic mission forms part of a five-year international research initiative called Constraining Ocean Carbon with Optimised Observing, commonly referred to as COCO2.
The programme aims to reduce uncertainty in estimates of the global carbon budget and improve scientific understanding of how carbon dioxide moves between the atmosphere, land and oceans.
A major component involves combining new observations with advanced modelling techniques and machine learning.
Scientists cannot realistically measure every location in the Southern Ocean continuously.
Instead, they must identify the regions, seasons and environmental conditions where additional observations would provide the greatest scientific benefit.
Machine learning can help researchers determine where measurements are most valuable by identifying patterns in existing observations, satellite information and climate-model outputs.
This approach could improve the efficiency of future ocean research while strengthening the accuracy of climate simulations.
Existing global climate models generally operate at spatial resolutions of approximately 100 kilometres.
Although these models are valuable for understanding broad climate patterns, they cannot fully represent smaller ocean processes such as swirling eddies, ocean fronts and rapidly changing currents.
These processes influence how carbon dioxide moves between seawater and the atmosphere.
Improving observations could therefore help researchers understand why different climate models sometimes produce conflicting estimates of Southern Ocean carbon absorption.
South Africa Strengthens Its International Climate Science Role
South Africa’s participation builds on nearly 15 years of investment in ocean-climate research through SOCCO.
The programme is hosted by the CSIR and receives substantial support from the Department of Science, Technology and Innovation.
Over time, South African researchers have developed expertise in ocean carbon measurements, satellite remote sensing, autonomous observing technologies, high-resolution climate modelling and machine learning.
This scientific capability has positioned South Africa as an important contributor to international research on ocean circulation and climate change.
The Antarctic mission brings together researchers from CSIR, Australia’s Commonwealth Scientific and Industrial Research Organisation, the United States National Oceanic and Atmospheric Administration, Columbia University and the University of Washington.
Saildrone supplies and operates the autonomous vessels, while Schmidt Sciences provides philanthropic funding through its Virtual Institute for the Carbon Cycle.
The partnership illustrates how international scientific collaboration can combine technological innovation, specialised expertise and financial support to investigate environmental challenges that transcend national boundaries.
For South Africa, the project also strengthens opportunities for scientific training, technological development and participation in global climate research networks.
Why the Southern Ocean Matters to South Africans
Although Antarctica appears geographically distant, its environmental influence extends directly into Southern Africa.
The Southern Ocean influences atmospheric circulation, regional weather systems and rainfall patterns affecting South Africa.
Changes in ocean temperatures, currents and heat distribution can influence the climate conditions that shape agricultural production, water availability and food security.
Dr Thomalla has highlighted the region’s proximity, noting that the Southern Ocean is much closer to South Africa than many people assume.
Its influence on rainfall and weather systems means that scientific discoveries concerning the ocean could eventually improve understanding of environmental risks affecting communities across the country.
More accurate climate models could help researchers assess potential changes in rainfall distribution, drought conditions and extreme weather patterns.
These improvements would be particularly valuable for a country already experiencing climate-related pressures involving water resources, agriculture and infrastructure.
Implications for Global Climate Policy
The findings from the COCO2 programme are expected to contribute to international assessments of the global carbon budget.
The Global Carbon Budget tracks emissions generated by human activities and estimates how much carbon dioxide remains in the atmosphere or is absorbed by natural systems, including land and oceans.
The Southern Ocean’s role is particularly important because uncertainty surrounding its carbon absorption capacity affects estimates of how rapidly atmospheric greenhouse gas concentrations may increase.
The observations collected during the Antarctic mission are expected to inform scientific assessments used by the Intergovernmental Panel on Climate Change.
Such information can help policymakers understand the effectiveness of natural carbon sinks and evaluate the implications of changing environmental conditions.
However, scientists caution that natural carbon absorption should not be treated as a substitute for reducing human-generated greenhouse gas emissions.
The oceans can absorb substantial quantities of carbon dioxide, but their capacity is neither unlimited nor guaranteed to remain unchanged under continued warming.
Reliable scientific measurements are therefore essential for assessing climate risks and designing effective mitigation strategies.
Environmental Technology Offers New Research Opportunities
The Antarctic mission demonstrates how technological innovation is transforming environmental research.
Autonomous vessels can collect observations in remote environments where human access is difficult, expensive or dangerous.
Satellite communication enables researchers to monitor operations and adjust missions without physically accessing the vessels.
Meanwhile, machine learning can help interpret complex datasets and identify opportunities for more efficient scientific observation.
Together, these technologies offer new possibilities for studying oceans, atmospheric conditions and environmental systems across the planet.
Nevertheless, autonomous research platforms should complement rather than replace traditional scientific expeditions.
Research ships remain essential for collecting specialised measurements, conducting experiments and validating observations obtained through remote systems.
The strongest scientific results are likely to emerge from combining autonomous platforms, satellite observations, conventional expeditions and advanced modelling.
Conclusion: A New Chapter in Antarctic Climate Research
South African scientists’ participation in the Antarctic Saildrone mission represents an important contribution to international environmental science.
By investigating the Southern Ocean during its most challenging season, researchers hope to close a major observational gap and improve understanding of how oceans regulate the global climate.
The combination of autonomous sailing technology, satellite communication, machine learning and oceanographic expertise offers a promising approach to studying remote environmental systems.
For South Africa, the project reinforces the importance of investing in scientific capacity, international partnerships and technological innovation.
Ultimately, improved understanding of the Southern Ocean could strengthen climate forecasting, support environmental policymaking and help communities prepare for a changing climate.
As the autonomous vessels navigate Antarctica’s stormy waters, the observations they collect may provide essential evidence about the future of Earth’s climate system.
The mission also demonstrates that South African science is contributing directly to some of the world’s most important environmental research efforts, helping generate the knowledge required to understand and respond to climate change.
