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Researchers at the University of Southampton have captured unprecedented data about some of the coldest abyssal ocean waters on Earth - known as Antarctic Bottom Water - during the first voyage of the yellow robotic submersible known as Boaty McBoatface, which arrived back in the UK last week.

Boaty McBoatface being deployed from the ship

The team, which also involved scientists from the British Antarctic Survey and engineers from the National Oceanography Centre, captured data on temperature, speed of water flow and underwater turbulence rates of the Orkney Passage, a region of the Southern Ocean which is around 4,000m deep and roughly 500 miles from the Antarctic Peninsula.

In order to visualise the progress of Boaty and place the data in the context of the complicated terrain in the region, the team have created an animated fly-through of the Orkney Passage - external link. The information collected will now be analysed to understand the complex process of ocean mixing and how it affects climate change.

The information was gathered as part of the Dynamics of the Orkney Passage Outflow (DynOPO) seven-week expedition, with the RRS James Clark Ross returning to Southampton last week. The DynOPO programme is funded by a NERC grant.

It was the first Antarctic voyage of Boaty McBoatface, one of the Autosub Long Range (ALR) class of unmanned submersibles, the latest type of autonomous underwater vehicle (AUV) developed by the National Oceanography Centre. The Autosub was named following last year's campaign by NERC to name the UK's new polar research ship. While the ship will be named after famous naturalist and broadcaster Sir David Attenborough, the popular suggestion of the contest - Boaty McBoatface - lives on in the form of an unmanned submersible that will support the research ship to explore parts of the polar regions inaccessible to humans.

Welcoming Boaty McBoatface back from its first mission, Universities & Science Minister Jo Johnson, said:

Fresh from its maiden voyage, Boaty is already delivering new insight into some of the coldest ocean waters on Earth, giving scientists a greater understanding of changes in the Antarctic region and shaping a global effort to tackle climate change. Future Boaty missions and the new RRS Sir David Attenborough research vessel will ensure the UK continues to punch above its weight and lead the way in polar science, engineering and technology as part of our industrial strategy.

Researchers used a combination of specialised instruments, including those deployed from the ship, as well as instruments moored to the seafloor, and measurements made by Boaty.

The submersible completed three missions during the expedition, the longest lasting three days, travelling more than 180km and reaching depths of nearly 4,000m. It travelled back and forth through an abyssal current of Antarctic Bottom Water (AABW) along the Orkney Passage, sometimes in water colder than 0°C and in currents up to 1 knot, while measuring the intensity of the turbulence.

This current forms off the coast of Antarctica as cold winds off the ice sheet cool the sea surface. The resulting cold, dense water sinks and moves northwards, forming an important part of the global circulation of ocean water. The Orkney Passage is a key chokepoint that AABW has to navigate on its way from Antarctica's Weddell Sea to the Atlantic Ocean.

Current evidence suggests that changing winds over the Southern Ocean affect the speed of seafloor currents carrying AABW. The speed of these currents determines how turbulent their flow is around underwater mountain ranges (submarine topography). Faster flow is more turbulent, and in this turbulence more heat is mixed into AABW from shallower, warmer ocean layers - thus warming the abyssal waters on their way to the Equator, affecting global climate change.

Professor Alberto Naveira Garabato from the University of Southampton, the lead scientist of DynOPO, said:

The Orkney Passage is a key chokepoint to the flow of abyssal waters in which we expect the mechanism linking changing winds to abyssal water warming to operate. Our goal is to learn enough about these convoluted processes to represent them (for the first time) in the models that scientists use to predict how our climate will evolve over the 21st century and beyond.

We have been able to collect massive amounts of data that we have never been able to capture before due to the way Boaty (Autosub Long Range) is able to move underwater. Up until now we have only been able to take measurements from a fixed point, but now we are able to obtain a much more detailed picture of what is happening in this very important underwater landscape. The challenge for us now is to analyse it all.

But the expedition was not without its challenges. Povl Abrahamsen, Physical Oceanographer at the British Antarctic Survey, explained:

At the start of one mission, whilst diving, Boaty encountered a swarm of krill so dense that the sub's echo sounders thought it was approaching the seabed, although it was only at 80m depth, and returned to the surface. However, the upside was that we did see lots of whales near the ship! In spite of the occasional hiccup, and in increasingly cold and dark conditions, Boaty has gathered a unique and exciting dataset that we look forward to studying in more detail in months and years to come.

Steve McPhail, Head of AUV Development at the National Oceanography Centre, added:

Although these recent deployments tested the technological capabilities of Autosub Long Range, we are extremely pleased with the results and the data that we have been able to provide to the scientific community. In the near future, we are looking forward to expanding and developing the fleet on the success of this last mission.

Further information

Mary Goodchild
NERC News & Media Officer
01793 411939
marodc@nerc.ac.uk

Becky Attwood
Media Relations Officer
University of Southampton
02380 593212
07342 060429
r.attwood@southampton.ac.uk

Athena Dinar
Senior Communications Manager - Science
British Antarctic Survey
01223 221441
07909 008516
jonann@bas.ac.uk

Leigh Marsh
Communications Officer
National Oceanography Centre
02380 596170
07769 642286
leigh.marsh@noc.ac.uk

Notes

1. The British Antarctic Survey (BAS), an institute of NERC, delivers and enables world-leading interdisciplinary research in the polar regions. Its skilled science and support staff based in Cambridge, Antarctica and the Arctic work together to deliver research that uses the polar regions to advance our understanding of Earth as a sustainable planet. Through its extensive logistic capability and know-how, BAS facilitates access for the British and international science community to the UK polar research operation. Numerous national and international collaborations, combined with an excellent infrastructure, help sustain a world-leading position for the UK in Antarctic affairs.

2. The National Oceanography Centre (NOC) is the UK's leading institution for integrated coastal and deep ocean research. NOC undertakes and facilitates world-class, agenda-setting scientific research to understand the global ocean by solving challenging multidisciplinary, large-scale, long-term marine science problems to underpin international and UK public policy, business and wider society outcomes. NOC operates the Royal Research Ships James Cook and Discovery and develops technology for coastal and deep ocean research. Working with its partners, NOC provides long-term marine science capability including: sustained ocean observing, mapping and surveying, data management and scientific advice. NOC is wholly owned by NERC.

3. The University of Southampton drives original thinking, turns knowledge into action and impact, and creates solutions to the world's challenges. They are among the top 1% of institutions globally. Their academics are leaders in their fields, forging links with high-profile international businesses and organisations, and inspiring a 24,000-strong community of exceptional students, from over 135 countries worldwide. Through their high-quality education, the university helps students on a journey of discovery to realise their potential and join their global network of over 200,000 alumni.

4. Ocean & Earth Science (OES) at the University of Southampton has a well-established reputation for outstanding research and teaching. Their unique waterfront campus at the National Oceanography Centre Southampton attracts prominent researchers and educators from around the world, who join them to work within the areas of geochemistry, geology and geophysics, marine biogeochemistry, marine biology and ecology, palaeoceanography and palaeoclimate, and physical oceanography. Following publication of the national Research Excellence Framework 2014 (REF2014), OES was ranked second in the UK for proportion of research recognised as world-leading (4*) in the Earth Systems & Environmental Sciences Unit of Assessment.

5. NERC is the UK's main agency for funding and managing research, training and knowledge exchange in the environmental sciences. Our work covers the full range of atmospheric, Earth, biological, terrestrial and aquatic science, from the deep oceans to the upper atmosphere and from the poles to the equator. We coordinate some of the world's most exciting research projects, tackling major issues such as climate change, environmental influences on human health, the genetic make-up of life on Earth, and much more. NERC is a non-departmental public body. We receive around £330 million of annual funding from the Department for Business, Energy & Industrial Strategy (BEIS).