The devastating implications of changes in deep ocean currents for the world's climate could last for centuries, scientists have warned (Photo: AFP)
By AFP - Agence France Presse
Melting Antarctic sea ice causes ocean storms, scientists say
The record retreat of Antarctic sea ice by 2023 has led to more frequent storms in newly exposed parts of the Southern Ocean, according to a study published on Wednesday.
Scientists know that the loss of Antarctic sea ice can decrease the number of penguins, cause ice shelves to melt in warmer waters, and prevent the Southern Ocean from absorbing carbon dioxide.
But this new research, published in the peer-reviewed journal Nature, explores another consequence: the increased loss of heat from the ocean to the atmosphere and the consequent increase in storms.
Since 2016, there has been a large-scale reduction in Antarctic sea ice, but nothing like 2023, when a record amount failed to form during the winter.
For this study, Simon Josey, from the UK's National Oceanography Center, and his colleagues focused on three regions that showed exceptionally high levels of sea ice retreat that year.
Using satellite images, oceanic and atmospheric data, and wind and temperature measurements, they found that some newly ice-free areas suffered twice as much heat loss compared to a more stable period before 2015.
This was accompanied by “increases in the frequency of atmospheric storms” in previously ice-covered regions, the authors found.
“In regions of declining sea ice, the frequency of storms in June-July increased by up to 7 days per month in 2023 compared to 1990-2015.”
The heat loss caused by reduced sea ice could have implications for the way the ocean circulates and the wider climate system, the study added.
The oceans are a crucial climate regulator and carbon sink, storing more than 90% of the excess heat trapped near the Earth's surface by greenhouse gas emissions.
In particular, the retreat of sea ice could mean changes in the way a deeper layer of cold, dense water at the bottom of Antarctica absorbs and stores heat.
The authors said that further analysis of possible climate impacts is needed, including whether retreating sea ice could have even more far-reaching consequences.
“Repeated conditions of low ice cover in subsequent winters will strengthen these impacts and probably also lead to profound changes elsewhere, including the tropics and the Northern Hemisphere,” they said.
myr/np/jj
Comentarios