How Southern Ocean Waves Affect Antarctic Ice: New Research

Scientists at New Zealand's National Institute of Water and Atmospheric Research (NIWA)
have made a breakthrough in understanding one of the key processes driving changes in sea ice.

Drs Alison Kohout, Mike Williams and Sam Dean along with Australian based scientist Dr Mike Meylan, have been researching how the Southern Ocean’s biggest waves are affecting Antarctic sea ice, explains NIWA.

Their new data show that large waves in the Southern Ocean - those bigger than 3 m - are able to break sea ice over greater distances than previously believed, and that this process may be the missing science that explains the increase in Antarctic, and rapid decrease in Arctic, sea ice extent.

Dr Kohout said the research aims to explain how Antarctic sea ice has been able to increase in some areas yet decrease in others.  This observed change is in contrast to the predictions from climate change models that Antarctic sea ice should have already begun retreating. It also potentially explain the accelerating loss of Arctic sea ice.

“Our work has suggested that the role of large waves is more relevant that previously assumed,” she said.

“In the Arctic there is a lot of evidence of sea ice retreat, yet scientists have been unable to reproduce the speed of sea ice retreat in their modelling. This suggests something is missing from the models.”

Sea ice plays a critical role in moderating the global climate system.  The state of the sea ice is an indicator of how climate is changing around the poles.

Dr Kohout said the Southern Ocean is continually generating large and unforgiving swells that break sea ice apart, removing the barrier between the ocean and atmosphere.

Source: National Institute of Water and Atmospheric Research