HONG KONG (Reuters) – Heat waves deep in the oceans may be “significantly under-reported”, highlighting an area of ocean warming that has been largely overlooked, according to a joint study by the Australian National Science Agency (CISRO) and the Chinese Academy of Sciences. .
The study, published on Thursday in the scientific journal Nature, found that 80% of heat waves at sea below 100 meters are independent of events on the surface.
It says researchers used observational data from more than two million ocean temperature profiles from the world’s oceans.
“These findings deepen our understanding of the frequency and intensity of extreme temperature events below the ocean surface and their potential implications,” said Ming Feng of CISRO.
Marine heat waves are long-lasting temperature events that can cause serious damage to marine habitats, such as impacts to coral reefs and species displacement, the study said.
These events are becoming more common due to global warming and are causing “catastrophic environmental and socio-economic consequences,” the report said.
The majority of previous studies of marine heat waves have focused on surface signals based on publicly available satellite observations of sea surface temperatures.
The finding of separate, deeper warming was particularly concerning, the study found, because it affects the habitats of so many creatures and what they feed on.
“Extreme temperature events below the sea surface are of greater ecological importance because they affect the habitat of most primary producers and consumers of the sea,” the report said.
The study also highlighted the influence of ocean currents, particularly eddies, on marine heat waves, indicating that they are a major driver of subsurface events, CISRO said.
Ocean gyres can affect acidification, oxygen levels and nutrient concentrations in the ocean.
Understanding the causes of subsurface marine heat waves, such as eddies, will help improve assessment of these events in a warming climate and help predict them in the future, the report said.
(Reporting by Farah Master and the Beijing newsroom; Editing by Barbara Lewis)