Rothera Time Series

The Rothera Time Series (RaTS) is a programme of Sustained Observation focussed on crucial Earth System indicators in Antarctica that are vital to UK and global science.

National Capability Science

The programme comprises an integrated suite of oceanographic and biochemistry data (e.g., temperature, salinity, macronutrients, chlorophyll) collected at a key site of rapid climate warming and high inter-annual variability on the Antarctic Peninsula.  The Programme is funded by NERC’s as National Capability Single Centre.  Data from the programme support a wide range of research by UK and international collaborators.

Sustained observations are vital for understanding change

Changes in the ocean/climate system can occur over decades, and these changes are best detected using continuous, long-term monitoring programmes. The Rothera Time Series (RaTS) is one of the most important long-term monitoring programmes in Southern Ocean science, partly because it features winter-time measurements that are difficult to obtain.

Optimising expertise and facilities

Interpreting ocean time series measurements requires knowledge of their representativeness over large spatial scales; to this end, a component of RaTS based on autonomous ocean gliders has been developed, with three summer seasons of glider deployments now completed. This work is conducted in collaboration with partners at NOC and Teledyne Webb Research (US). Our vision is to continue to develop RaTS into a fully-fledged UK Southern Ocean Observatory, by enhancing the glider operations and capability at Rothera, and by deploying other new technological assets (smart moorings, etc) to progress even further our understanding of this key region of rapid change.

RaTS upper-ocean series of potential temperature, salinity and sea ice cover from Jan 1998 to Dec 2012.

Scientific rationale

The western Antarctic Peninsula (WAP) is the most rapidly-warming region in the Southern Hemisphere. Atmospheric temperatures here have risen by nearly 0.4°C/decade during the second half of the twentieth century, with associated rapid retreat of the majority of glaciers, collapses of ice shelves, and a dramatic decline in sea ice. The ocean in this sector of the Southern Ocean has warmed very dramatically during this period, with surface temperatures increasing by over 1°C in summer. Most climate models predict warming around the rest of Antarctica during the course of the coming century, but perform very poorly at reproducing past change; there is thus a critical need to fully understand ocean-atmosphere-ice feedbacks in regions of rapid change, and to use this knowledge to verify and improve these models. There is also a key requirement to understand the impacts of rapid ocean warming and increasing ice loss on the biogeochemical system, so that the consequences for marine productivity and carbon drawdown from the atmosphere can be projected, and the vulnerability of the marine ecosystem to future climate change determined.

National and International Context

RaTS is operated by the British Antarctic Survey, but functions as a genuinely UK-wide effort. Numerous grants have been won by UK HEI collaborators to work at Rothera to exploit the infrastructure and scientific context provided by RaTS, with partners from UEA, Southampton, Edinburgh, Oxford, Bristol and many others each having brought unique measurement capability and scientific expertise into the collaboration. Other NERC labs (BGS, NOC) are key partners, providing ocean technology expertise and contributing unique capability with sample analysis. Currently RaTS provides the central focus for two NERC Independent Research Fellows, Dr. Alex Brearley (BAS) and Dr. Sian Henley (Edinburgh).

In the international context, RaTS constitutes a key UK contribution to the US-led Palmer Long-Term Ecological Research (Pal-LTER) program, operated out of Palmer Station further north on the WAP. This key link enables sharing of expertise and cross-calibration of equipment, plus greatly enhanced scientific output, visibility and impact. RaTS has also been central to many of the projects funded by the Dutch Antarctic programme, which has included the building of a new laboratory complex at Rothera. This international partnership, funded by the Netherlands Polar Programme, has enabled the development of the RaTS collaboration along scientific avenues that would not have been otherwise possible, generating significantly enhanced scientific output and impact.

Enhancing knowledge to address global issues

RaTS commenced in 1997 with the intention of making the high-quality ocean measurements required to fully understand ocean-atmosphere-ice feedbacks in regions of rapid change, and to use this knowledge to verify and improve these models. There is also a key requirement to understand the impacts of rapid ocean warming and increasing ice loss on the biogeochemical system, so that the consequences for marine productivity and carbon drawdown from the atmosphere can be projected, and the vulnerability of the marine ecosystem to future climate change determined.

Its longevity and sustained high frequency of sampling (quasi-weekly) enables unparalleled quantification and understanding of seasonal, interannual and decadal changes in this climatically-sensitive ocean. It involves profiling of the physical properties (temperature, salinity, density) of the water column at the WAP using rigid inflatable boats as platforms, plus sampling for a range of biogeochemical and biological parameters. Measurements are made either in the Bonner Laboratory at Rothera, or in the UK after shipping of samples. The suite of measurements includes chlorophyll concentration, nutrients, isotopic tracers of ice melt, carbonate system parameters, and many more. Linked to the atmospheric and ice sustained observations at Rothera, RaTS represents one of the most comprehensive suite of time series measurements made anywhere in the Southern Ocean. Uniquely, it includes full winter-time ocean measurements, including sampling though holes cut in sea ice when the ocean surface is completely frozen; these winter measurements have enabled some of the most important new insights into the functioning of the oceanographic and biological systems to be obtained.

Key findings

RaTS data have led to fundamental advances in our understanding of ocean changes in an important region of rapid climate change. Recent noteworthy highlights include:-

• Detection of new feedbacks between the ocean, ice and atmosphere, with relevance for the rest of the Southern Ocean as climate change progresses.

• Understanding of the role of ocean dynamics in redistributing the extra glacial melt coming from Antarctica, with implications for fertilization of plankton blooms by micronutrients such as iron.

• Detection of a marked decline in ocean phytoplankton on a decadal timescale, triggered by changing ocean structure caused by the loss of sea ice; this has great relevance around the rest of Southern Ocean as the sea ice is lost in future decades.

• New understanding of the sensitivity of the WAP ocean to forcing by large-scale modes of climate variability (including the El Nino/Southern Oscillation phenomenon), highlighting the susceptibility of the sea around Antarctica to global forcing changes.

1. Rothera Marine Team – Overcoming challenges

   Working in Antarctica often means making the best out of what you got. For the Rothera 2022 wintering team, this meant spending a winter without diving, which had to be […]

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2. Bonner Laboratory featured at Global Biodiversity Festival 2021

   Rothera Marine Biologist Nadia Frontier and Rothera Marine Assistant Ryan Mathews spoke about the work of the Bonner Laboratory and dive facility at Rothera Research Station during the Global Biodiversity […]

   Read more of: Bonner Laboratory featured at Global Biodiversity Festival 2021

   

3. Celebrate International Day of Women and Girls in Science 2018

   To celebrate International Day of Women and Girls in Science (11th February), Zoe Waring, the Marine Assistant at Rothera Research Station, has written a blog about her work at British […]

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4. GUEST BLOG: Ready for Antarctic trip number five!

   Find out about NERC Research Fellow Dr Sian Henley’s preparations for her fifth visit to Rothera Research Station and what she looks forward to onboard the RRS James Clark Ross.

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1. British Antarctic Survey’s 2021-2022 field season is underway

   Science and support teams from British Antarctic Survey (BAS) are gearing up for the start of the Antarctic summer field season. All five of our research stations will be open […]

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2. Warming Western Antarctic Peninsula waters impact plankton community

   Warming water and receding sea ice in the Western Antarctic Peninsula is changing the local plankton community with potential consequences for climate change, according to an international team of researchers. […]

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3. PRESS RELEASE: New season – ambitious science

   New season tackles ambitious science and logistical challenges The British Antarctic Survey (BAS) 2015/16 field season is underway with dozens of scientists and support staff – together with planes and tonnes […]

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The seas around Antarctica are climatically very important, being intimately connected to the rest of the Earth System via the global ocean overturning circulation. However, Antarctica may have already passed significant tipping points, moving into a “new normal” of extreme events including record temperatures and sea ice minima. It is imperative that we understand in detail the key processes involved, so that we can better predict the regional impacts on marine ecosystems and the global consequences for society. The west Antarctic Peninsula (wAP) is a key study site, being amongst the most susceptible to many of the rapid changes observed and predicted.

The BAS Polar Oceans (PO) Team and the UK Polar Data Centre (PDC) have a long-lasting collaboration in curating, preserving and distributing data from the Rothera Oceanographic and Biological Time Series (RaTS).  Collection of these data began in 1997 in Ryder Bay, an enclosed part of Marguerite Bay on the wAP, and is ongoing to this day.  The time series includes water column profile data (such as temperature, salinity, fluorescence) and discrete sample measurements (ammonium, nitrate, nitrite, phosphate, silicic acid and oxygen isotopes), which inform on physical and biogeochemical ocean variability on timescales from days to decades. Direct observations of sea ice conditions are also collected. In November 2022, PO Scientists and PDC Data Managers published the first 20-year tranche of data (1997-2017), quality controlled and validated, and now made available to scientists around the world. The intention is that this dataset will be updated on a five-yearly basis.

This time series is one of the longest systematic year-round resources for investigations of climate change impacts on the ocean and ecosystem, and their feedbacks. It has also been used extensively by both UK and international researchers as a tool for providing longer-term climate context to more specialist studies in subjects as diverse as dimethyl sulphide production to ocean turbulence.

Data are available from the UK PDC at https://doi.org/10.5285/50ACB5B7-5B42-44CD-A98E-790BD367F204.

The Rothera Time Series data have been presented and described in detail in the Nature Scientific Data article:

Venables, Hugh, Meredith, Michael P., Hendry, Katharine R., ten Hoopen, Petra, Peat, Helen, Chapman, Alice, Beaumont, Jennifer, Piper, Rayner, Miller, Andrew J., Mann, Paul, Rossetti, Helen, Massey, Ali, Souster, Terri, Reeves, Simon, Fenton, Mairi, Heiser, Sabrina, Pountney, Sam, Reed, Sarah, Waring, Zoë, Clark, Marlon, Bolton, Emma, Mathews, Ryan, London, Hollie, Clement, Alice, Stuart, Emma, Reichardt, Aurelia, Brandon, Mark, Leng, Melanie, Arrowsmith, Carol, Annett, Amber, Henley, Sian F., Clarke, Andrew. (2023) Sustained, year-round oceanographic measurements from Rothera Research Station, Antarctica, 1997-2017. Scientific Data, 10. https://doi.org/10.1038/s41597-023-02172-5.

1. Rothera Research Station

   The largest British Antarctic facility is a centre for biological research and a hub for supporting deep-field science.

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2. Bonner Laboratory and dive facility

   Supporting near-shore marine biology

   Read more of: Bonner Laboratory and dive facility