SYDNEY, June 5 (Xinhua) -- Australian scientists have revealed the unprecedented North Atlantic heatwave in 2023 was driven by record-breaking weak winds, increased solar radiation, and ongoing climate change.
The North Atlantic Ocean experienced a basin-wide marine heatwave in the summer of 2023, with water temperatures rising at a rate equivalent to two decades' worth of typical warming in just a few months, said a new study led by researchers from the University of New South Wales (UNSW) on Thursday.
While marine heatwaves are usually short-lived, the 2023 event was remarkable not only for its speed and scale but also for its lasting impact, with elevated temperatures persisting for more than a year, said a release from the UNSW Sydney.
The research team identified record-weak winds across the North Atlantic in June and July 2023 as the main cause of the heatwave. Normally, winds mix the ocean's upper layer and spread heat deeper, but unusually calm conditions left this layer much thinner, sometimes only 10 meters deep instead of the usual 20 to 40.
As a result, the sun's energy heated the surface waters far more quickly than normal, the release said, adding climate change played a critical role in amplifying the effect.
The study, published in Nature, also found that reduced sulphur emissions from ships, due to 2020 regulations, led to clearer skies and less cloud cover over shipping lanes. This allowed more sunlight to reach the ocean, further intensifying local warming.
"While these extreme temperature events are typically only temporary, we can expect they'll become more frequent in the future," said the study's lead author Matthew England, a professor from UNSW Sydney.
The marine heatwave had widespread impacts: Europe faced deadly 40-degree Celsius heatwaves and severe floods, Caribbean coral reefs suffered bleaching, and stronger Atlantic storms in Florida caused significant destruction, said the researchers from UNSW Sydney and the Australian National University.
England emphasized the urgent need to end fossil fuel use, warning that without swift climate action, severe and costly extremes will worsen. ■
