A new study shows how sea waves in the Antarctic are causing ice to break and melt rapidly.
NIWA scientists observed that the Southern Ocean's biggest waves affected the Antartic's sea ice. The research showed how large waves bigger than 3 meters in the Southern Ocean could break sea ice over greater distances than previously known. The discovery may just be the missing link that could shed light on the increase in Antarctic and rapid decrease in Arctic sea ice extent.
Drs Alison Kohout, Mike Williams, and Sam Dean worked with Australian-based scientist Dr. Mike Meylan to conduct the study, in hopes of finding out how Antarctic sea ice came to increase in some areas but decrease in other areas – an observation that opposed previous predictions from climate change models that stated Antarctic sea ice should be receding. The results also explained the rapid loss of Arctic sea ice. The researchers used new technology, including autonomous equipment, to collect data for the study.
"Our work has suggested that the role of large waves is more relevant than previously assumed. In the Arctic there is a lot of evidence of sea ice retreat, yet scientists have been unable to reproduce the acceleration of sea ice retreat in their modeling. This suggests something is missing from the models," Kohout said in a press release.
Sea ice is important in moderating the global climate system. It covers 30 percent of the ocean in the south of New Zealand in the winter, becoming a barrier that separates the atmosphere from the ocean. It also indicates how climate changes around the poles.
According to Kohout, the Southern Ocean incessantly produced large swells that break sea ice apart, resulting in the disappearance of the barrier between the ocean and the atmosphere.
The researchers believed that their findings could help improve ship navigation.
“We will be able to predict the size of waves that ships can expect when they are moving through sea ice. This is important as large waves can be a risk to ships with little or no ice protection," Williams said in a press release.
Full details of the study were published in the May 28 issue of Nature.
