Huge ocean "eddies", swirling currents up to 60 miles wide are becoming more energetic worldwide – and it could have important effects on climate change.
The amount of energy in the currents has increased in the last three decades, according to research published in the journal Nature Climate Change.
Researchers fear the changes to eddies could impact the ability of oceans to absorb heat and CO2 – with huge knock-on effects.
The ocean has absorbed about 90% of global heating since the 1970s and has also pulled in about 40% of the extra carbon dioxide emitted into the atmosphere, The Guardian reports.
Researchers analysed data from 1993 to 2020, and found that, on average, eddies are becoming more than 5% more energetic each decade.
Prof Matthew England, of the Climate Change Research centre at the University of New South Wales, said: “We know these eddies play an important role in the climate, but how this intensification might change a given weather pattern is hard to say.
Ocean eddies have been growing more energetic worldwide (NASA)
Ocean eddies have been growing more energetic worldwide. (Nasa)
“To see it changing at this scale to me is confronting.
"To see these changes shows how much we are perturbing the system. There will be impacts on our climate and ecosystems that we will have to explore now.”
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The researchers, led by Navid Constantinou, Research Fellow at the Australian National University, wrote in The Conversation: “By carefully analysing satellite observations, our team discovered clear changes in the distribution and strength of ocean eddies. And these changes have never been detected before.
“Scientists have known for decades that eddies in the Southern Ocean affect the overturning circulation of the ocean.
"As such, changes of the magnitude observed for eddies could impact the rate at which the ocean draws down heat and carbon.
“The impact of eddies is therefore either not resolved in climate projections, or is severely underestimated. This is particularly concerning in light of our discovery eddies are becoming more energetic.
“Our research emphasises how crucial it is to incorporate ocean eddies into future climate projections. If we don't, we could be overlooking a critical detail.”