But you're keeping warm, as you're hauling scientific equipment through a hole in the sea ice from the depths to the surface – hand-winching over 500 metres of wire to collect precious oceanographic data. And you know that you’re contributing to one of the most extraordinary long-term datasets in marine science, one that has required someone to winch this equipment up-and-down – hundreds of metres – over 2000 times.

And collecting oceanographic data and water samples is just one of the jobs carried out by the Rothera Marine Assistant, an over-wintering role in the Bonner Laboratory at Rothera Research Station on Adelaide Island, off the West Antarctic Peninsula.

The seas around Antarctica, including the West Antarctic Peninsula, are intimately connected to the rest of the Earth system and play an incredibly important role in global climate. Firstly, processes on the Antarctic shelves lead to the formation of some of the densest waters in the global ocean circulation system that moves heat, carbon and nutrients around the world. Secondly, these coastal waters are biologically rich due to the input of key nutrients from different sources. This means that a lot of carbon dioxide is taken up from the atmosphere as marine algae grow and form organic matter; as dead organic matter sinks, some of it will eventually be locked away within the marine sediments away from the atmosphere. Understanding the complex interactions between the oceans and climate is critical if we're going to make robust predictions about future environmental change. However coastal Antarctica is one of the most challenging places in the world to obtain marine data because of its remoteness and inhospitable nature, especially during the Antarctic spring and winter.

Since 1997, the Rothera Oceanographic Time Series (or RaTS) program has been in operation, providing a unique insight as data and samples are collected almost weekly throughout the year. The Rothera Marine Assistant, together with other scientists including international collaborators, sample the marine waters from a small boat during the summer and from a sled – when there is sea ice present in winter – through a hole that has been cut through the ice by a chainsaw. They winch a Conductivity Temperature Depth (CTD) sensor down and up to measure the physical properties of the water (such as temperature and saltiness), and then collect litres of seawater for chemical analysis. 

Scientists and data managers from the British Antarctic Survey have brought together the first 20 years of data from the RaTS programme to produce an Open Access FAIR (findable, accessible, interoperable and reusable) data product. Their data paper (Venables et al., 2023) describes the location, sampling, data processing, analytical methods, and quality control procedures used in gathering the time-series metadata and data. In producing this paper, the lead authors brought together all the past Rothera Marine Assistants who have worked in the Bonner Laboratory since the beginning, including tracking down those who now work in different sectors and those who have moved to different countries.

 As Science Leader, Professor Mike Meredith, says: “The data collected are unique and priceless, especially the data from the depths of the Antarctic winter when conditions are seriously challenging. That this time series has been sustained for over two decades with sampling every week is a massive achievement, and is testament to the awesome efforts of the field staff who have made it happen”.

"Sustained year-round oceanographic measurements from Rothera Research Station, Antarctica, 1997–2017" by Hugh Venables et al. is an open access publication in Nature Scientific Data, and is available here.

Blog by Prof Kate Hendry, an Ocean-Climate Scientist at the British Antarctic Survey, UK