Melting sea ice in Antarctica causes ocean storms, say scientists
Sign up now: Get ST's newsletters delivered to your inbox
Scientists know that the loss of Antarctic sea ice can diminish penguin numbers, cause ice shelves to melt in warmer waters and impede the Southern Ocean from absorbing carbon dioxide.
PHOTO: AFP
Follow topic:
PARIS – The record-breaking retreat of Antarctic sea ice in 2023 has led to more frequent storms over newly exposed parts of the Southern Ocean, according to a study published on Dec 18.
Scientists know that the loss of Antarctic sea ice can diminish penguin numbers, cause ice shelves to melt in warmer waters and impede the Southern Ocean from absorbing carbon dioxide.
But this new research, published in the peer-reviewed journal Nature, explores another consequence: increased heat loss from the ocean to the atmosphere and an associated rise in storms.
There has been a large-scale reduction in Antarctic sea ice since 2016, but nothing like in 2023, when a record amount failed to reform over the winter.
For this study, Professor Simon Josey of Britain’s National Oceanography Centre and colleagues focussed on three regions that experienced unusually high levels of sea ice retreat that year.
Using satellite imagery, ocean and atmospheric data and wind and temperature measurements, they found that some newly ice-free areas experienced double the heat loss compared with a stabler period before 2015.
This was accompanied by “increases in atmospheric-storm frequency” over previously ice-covered regions, the authors found.
“In the sea ice decline regions, the June-July storm frequency has increased by up to seven days per month in 2023 relative to 1990-2015.”
The loss of heat caused by reduced sea ice could have implications for how the ocean circulates and the wider climate system, the study added.
Oceans are a crucial climate regulator and carbon sink, storing more than 90 per cent of the excess heat trapped near earth’s surface by greenhouse gas emissions.
In particular, sea-ice retreat could mean changes in how a deeper layer of cold, dense Antarctic bottom water absorbs and stores heat.
The authors said further in-depth analysis of possible climate impacts were needed, including if sea-ice retreat could have even further-reaching consequences.
“Repeated low ice-cover conditions in subsequent winters will strengthen these impacts and are also likely to lead to profound changes further afield, including the tropics and the Northern Hemisphere,” it said. AFP
