Study: Around 16% of Antarctic Sea Ice Affected by Southern Ocean Waves

Melbourne (ANTARA) - Approximately 16% of Antarctic sea ice has been impacted by large waves from the Southern Ocean, according to a study led by Australian researchers.

The study provides a clear picture of a critical yet underdiscussed issue: the Marginal Ice Zone (MIZ).

Conducted by the University of Tasmania and published in Nature Communications, the research used long-standing satellite radar techniques applied to the French-Indian satellite in 2013 to measure wave heights entering sea ice over 12 years (2013-2024), according to a statement from the Australian Antarctic Program Partnership (AAPP) released on Thursday (28 May).

Unlike previous methods that defined MIZ based on arbitrary ice concentration thresholds, this approach measures the true definition per the World Meteorological Organization: ice affected by waves and swells from the open ocean, said study lead author Alex Fraser of AAPP, based at the University of Tasmania.

The study revealed that wave-affected MIZ forms a ring 35-180km wide around Antarctic sea ice, widest in winter and early spring when the ice edge meets high-wave regions of the Southern Ocean.

‘When sea ice is unaffected by waves, it forms a more intact ’cap’ over the ocean, limiting heat, moisture, and gas (such as carbon dioxide) exchange with the atmosphere. However, when waves shake and break the ice, gaps between ice floes allow for increased exchange,’ Fraser said.

Fraser added that the MIZ is also vital for protecting inner ice layers, fast ice, and ice shelves from waves, and supports marine life as meltwater at the shrinking ice edge fosters robust phytoplankton growth, which is food for krill, penguins, seals, and whales.

Researchers say understanding wave-ice interactions is key to explaining the sharp decline in Antarctic sea ice since 2016, adding that the findings will guide Australian icebreaker voyages to the East Antarctic MIZ in 2028.