The Southern Ocean is growing restless. Storms are increasing around Antarctica due to rampant sea ice loss in what researchers have described as a “shift unlike anything seen in the past century.”
In a new study, scientists at the UK’s National Oceanography Centre looked at the record low sea ice levels in the Antarctic during the winter of 2023 and its impact on stormy weather conditions.
During this unprecedented winter, sea ice concentrations in vast regions of the Weddell, Bellingshausen, and Ross seas plummeted by up to 80 percent below normal levels. This dramatic decline seems to have triggered ripple effects throughout the broader climate system of the continent.
Throughout the dark winter months, sea ice acts as a protective shield by limiting the transfer of heat from the relatively warmer ocean to the colder atmosphere above. When the blanket of ice is lost, heat is free to wander up into the atmosphere. Due to this effect, the researchers found that the loss of Antarctic sea ice in 2023 doubled the amount of heat being released into the atmosphere from the ocean in some areas.
Once in the atmosphere, heat can fuel storms by warming the air, causing it to rise rapidly, which triggers stronger winds, cloud formation, and turbulent weather systems. As such, it’s estimated that the ice loss in 2023 increased the frequency of storms in the worst-affected areas by up to seven days per month compared to the number seen between 1990 and 2015.
“For nearly 40 years, the amount of ice in the sea around Antarctica showed small but significant increases, culminating in a record high in 2014. But this was followed by a large loss of sea ice in 2016 and, in 2023, the losses were unprecedented, and a near-record low persisted in 2024,” Laura L. Landrum and Alice K. DuVivier, climate scientists at the National Center for Atmospheric Research in Colorado, wrote in an accompanying News & Views article.
“This decline, along with oceanic changes, suggest that the Southern Ocean could be going through a shift unlike anything seen in the past century,” they added.
Storms in Antarctica tend to occur in coastal regions because they’re driven by weather systems that originate over the Southern Ocean. Edges of the continent are also where low-pressure weather systems are formed by the clash between cold continental air and relatively warmer ocean air, adding to the likelihood of storms.
Marked by powerful winds, extreme cold, and heavy snowfall, Antarctic storms are typically more frequent and intense during the winter months. With the continent shrouded in perpetual darkness during this time of the year, these storms create an unforgiving environment.
If this research is anything to go by, these formidable weather events could become all the more common in the future.
“Just how anomalous was 2023? The Antarctic had extraordinarily little wintertime sea ice again in 2024. These two extreme winters might be part of a systemic change associated with a regime shift in the Southern Ocean,” concludes the study’s News & Views article.
The new study is published in the journal Nature.
