In recent years, scientists have seen some worrying changes in Antarctica. Research stations scattered across the ice sheets deep in the Antarctic interior have recorded air temperatures a stunning 40C warmer than normal in 2022, whilst the extent of sea ice that rings the frozen continent shrunk to record levels in summer 2023 and has still not recovered to its normal level in winter 2023.
This concerns scientists and policy makers because Antarctica holds some 60% of the world’s freshwater, locked in ice sheets that tower up to three miles above the ground they rest on. If that water was released into the ocean, it could raise global sea levels by 70 metres.
That won’t happen any time soon. But it’s hard to be more precise about how quickly, and how much of, Antarctica’s ice will melt away. And so, it’s difficult for coastal communities to prepare for how much sea levels might rise over the next few decades.
That’s because the Antarctic is among the most difficult places in the world to carry out research. The remote and often inhospitable nature makes fieldwork challenging. And the complexity of interconnected physical systems and many small-scale processes are difficult to recreate accurately in models. These challenges explain why many key Antarctic processes remain poorly understood and why we can’t yet forecast the future of the region, and wider impacts, with enough certainty.
Yet the world needs rapid progress on these critical knowledge gaps to support the goals of the United Nations’ Paris Agreement, to inform the ongoing international policy dialogue on how to address climate change, and to minimise the negative impacts of climate change.
The SURFEIT programme aims to make forecasts of sea level rise more reliable. It will do this by bringing together experts from around the world to improve how scientists understand interactions between snow, water, ice, and the atmosphere across Antarctica.
This information will be used to refine the computer models used to forecast changing conditions in Antarctica, and to make those models better able to focus on the impact of extreme weather events on specific geographical regions, such as a vulnerable part of a melting ice sheet.
In the scientific jargon, SURFEIT will do this by looking at mass and energy fluxes. In real terms, that means the movements of snow, ice, and water, and how these are influenced by sunlight, winds, ocean currents and rising temperatures.
For example, scientists aren’t yet sure on basic questions such as whether it will snow more or less in Antarctica as temperatures continue to rise. That’s a pivotal change because Antarctic snow comes from water evaporated from the ocean – water that will be stored away on land as snow and ice, and so won’t contribute to sea level rise. A big reason for the uncertainty is that the formation and behaviour of clouds in the region is something of a mystery.
SURFEIT aims to solve this mystery, by looking more closely at how to better model the way clouds form in the Antarctic atmosphere. Specifically, it will add to the models how small particles of salt and other materials are released into the atmosphere from the layers of snow that cover the Antarctic sea ice. Blown into the air, these small bits (called aerosols) hang suspended and offer a surface for water vapour to condense on, which helps the clouds to form. Understanding how this influences snowfall will allow the models to better track the relationship between sea ice changes and how much it will snow.
Ice sheets melt in different ways, and the SURFEIT team will address this. One poorly understood melting mechanism is how liquid water lying on top of ice can penetrate through cracks and crevasses and go on to cause further fracturing, until the ice shelf collapses. By building better models, the project will be able to simulate this cascading effect, as well as what happens when rain falls onto snow, and to compare the results with those produced using machine learning.
Fracturing of the floating ice shelves that ring Antarctica does not directly raise sea levels, but it can encourage the movement of land-bound ice towards the sea, which does. So, better models of ice fracturing will also help prepare better forecasts of how Antarctic ice shelves might contribute to future global sea level rise.
A big part of the SURFEIT programme is to make the data, results, and tools available to the broader community of international researchers, stakeholders, the public and policy makers. For example, the team will discuss the findings at scientific meetings and brief government science advisers. The improved models and expertise will be made available to future Antarctic scientists, to help them keep track of changes in this vital and influential part of the Earth’s climate system.