An iceberg is melting faster than conventional models report, according to a new study by mathematics at the University of Sydney. The researchers have proposed a new model to represent the melting speed of icebergs to oceans.
Their findings, published in Wet corporate review, has an impact on seafarers and climate scientists.
Lead author and PhD student Eric Hester said: “While an iceberg is only one part of the global climate system, our developed model provides us with a dial that we can tune to conventional climate. to capture the changing climate of the Earth. ”
Conventional models, incorporated into the approach taken by the Intergovernmental Panel on Climate Change, assume that an iceberg is melting uniformly in currents. ocean. However, Mr Hester and his colleagues have shown that an iceberg does not melt uniformly and melts at different speeds depending on the shape.
“Polar ice sheets contain around 70 per cent of the world’s freshwater and we know that climate change is causing these ice sheets to decline,” said Mr Hester, a doctoral student at the School. Mathematics & Statistics.
“Some of this ice loss is straight from the ice sheets, but about half of the total ice loss from Greenland and Antarctica occurs when an iceberg melts in the ocean, so it’s understandable. this process is important.
“Our model shows that an iceberg is melting at faster rates than conventional models,” he said.
In addition to his importance for shaping the changing nature of ice sheets, Mr Hester said his research would help us better understand the effects of ice melting on ocean currents.
“Ocean circulation is the reason Britain is not as cold as Alberta, Canada, despite being at the same level,” Mr Hester said.
The Gulf Stream, which brings warmer water from the tropics across the Atlantic, keeps western Europe calmer than it would otherwise be, he said.
“That flow could be closed if too much fresh water is thrown into the system at one time, so it’s vital that we understand the process of iceberg and ice melting.”
Where and when the freshwater is released, and how it affects the ocean, depends in part on the rate at which an iceberg melts.
Co-author Dr Geoffrey Vasil from the University of Sydney said: “Previous work involving the inclusion of an iceberg in climate simulations has used very simple melting models. We wanted to see how accurate these were and if we could make progress on them. ”
Mr Hester said their models have been tested in a trial – and collectors’ comments show that the sides of icebergs are melting about twice as fast as their base. For an ocean-moving iceberg, melting at the front can be three or four times faster than the old models predicted.
“The old models assumed that there was an iceberg of stationery will not melt at all, but our tests show a melting point of about a millimeter per minute, ”said Mr Hester.
“In an iceberg moving in oceans, the melting at the base can be up to 30 percent faster than in older models.”
The research shows that the shape of an iceberg is important. As the sides melt faster, a wide iceberg melts more slowly but a narrower iceberg melts faster.
“Our paper proposes a very simple model that describes the shape of an iceberg, as a prototype for an improved model of iceberg melting,” said Dr Vasil.
To test these models, the researchers first developed small samples of ice dissolved in salt water.
“We are confident that this modeling captures enough of the complexity so that we now have a better way of explaining how an iceberg is melting,” said Mr Hester.
Dr Vasil, Mr Hester’s PhD supervisor, said: “Before Eric embarked on his PhD, the computer devices to model these systems did not exist.
“Eric took a very simple prototype and made it work wonderfully on the complex ice-melting problem.”
Dr Vasil said these techniques can be applied to many other systems, including melting glaciers or melting frozen sea ice.
“But it doesn’t end there. Astrobiologists could use his techniques to better understand ice branches such as Enceladus Saturn, a candidate for finding life elsewhere in the Solar System. ”
The research was conducted in collaboration with scientists from the British Antarctic Study, the University of Canterbury in New Zealand and the Woods Hole Institute of Marine Science in Massachusetts, USA.
DOWNLOAD video of the exam, the academic paper and photos at this link.
EMBED YouTube video description (30 seconds) at this link.
READ an article about the research by the American Corporate Association at this link.