Spending three months inside a metal container on board an icebreaker in the Southern Ocean, filtering water while attempting to ignore freezing temperatures and huge ocean swells outside. It’s not everyone’s idea of fun … but it’s what I’ll be doing next year, in the name of climate science.
From late December 2016 to March 2017 I will be on board the Russian research vessel Akademik Treshnikov, taking part in an expedition that will take me and 54 other scientists from 30 countries on a complete lap of Antarctica – the first international research expedition to circumnavigate the frozen continent.
The Antarctic Circumnavigation Expedition (with the funky abbreviation ACE) is the first project run by the Swiss Polar Institute, and involves 22 projects covering different aspects of the biology, physics and chemistry of the Southern Ocean.
We’re not expecting the conditions to be particularly fun – but it will be worth it. A better understanding of Antarctica and the Southern Ocean surrounding it is critical – not just for the preservation of this pristine environment but also for the whole planet.
The Southern Ocean is massive. It is also really far away from everywhere, which makes it hard for scientists to go there and study it. On top of that, there is no land at these latitudes to stop waves from building up, so waves can get really big, making the Southern Ocean a less than ideal environment for scientific work. I’m expecting that all of us will get seasick at some point.
Because of the size and isolation, our understanding of the physics, chemistry and biology of the Southern Ocean is not very good. What we do know is that this region is disproportionately important for the planet’s climate. For example, it was responsible for storing an estimated 43% of the carbon dioxide produced by humans between 1870 and 2005, and 75% of the overall oceanic heat uptake.
The ACE expedition is a unique opportunity to collect data in the Southern Ocean. The voyage will set off from South Africa, visiting all of the Southern Ocean’s main islands and traversing a range of latitudes – visiting the Antarctic coast just once, at Mertz Glacier in East Antarctica.
By spending three months completing a full circuit of the ocean, we will be able to collect an unprecedented set of samples and measurements, which will greatly improve our understanding of the Southern Ocean.
My research is concerned with phytoplankton – microscopic algae that live in the sunlit surface layer of the oceans. Just like plants on land, phytoplankton in the oceans photosynthesise, using the energy from sunlight to “fix” carbon dioxide into organic biomass, producing oxygen as a by-product. The rate of this change in biomass is called primary productivity.
Phytoplankton primary production forms the base of marine food webs, making it a fundamental process of marine ecosystem dynamics and directly relevant to fishery yields.
It is also an important component of the carbon cycle, and therefore global climate dynamics. This is because through a process called the “biological pump” a fraction of the roughly 45 billion tonnes of carbon fixed by phytoplankton every year sinks out of the surface layer and is stored in the deep ocean, away from the atmosphere.
My colleagues and I are trying to improve our understanding of what controls the distribution of phytoplankton, the rates of primary productivity, and the variability in the biological pump in the Southern Ocean.
Unfortunately, even sending a shipload of scientist on a three-month voyage to the Southern Ocean to measure phytoplankton biomass, productivity, and other chemical and physical factors, can only provide a snapshot of what is really going on. Ideally, we need to monitor the whole Southern Ocean over seasons, years, and decades. And this can actually be done, with the help of a technique called satellite ocean colour radiometry.
The main focus of our research is the collection of so-called “bio-optical” data, which will improve our ability to interpret satellite observations and derive better estimates of phytoplankton biomass and productivity in the Southern Ocean. This, in turn, will allow us to use past satellite records to determine how phytoplankton biomass and productivity has changed over the past decades, and help to establish possible connections to ongoing climate change.
It also means that we will be able to use satellite data to monitor, essentially in real time, what is happening to phytoplankton biomass and productivity in the Southern Ocean, without having to rely on frequent and extensive expeditions. But in the meantime, I’ll be more than happy to be part of this adventure.