Marine heat waves more than 200m below the ocean surface
A joint study conducted by Australia’s national science agency, CSIRO, and the Chinese Academy of Sciences has revealed alarming insights into marine heatwaves occurring below the ocean’s surface, which may be largely overlooked. Published on Thursday in the journal “Nature”, the research highlights that up to 80% of these heatwaves, located deeper than 100 meters, are independent of surface temperature events.
Utilizing observational data from over two million ocean temperature profiles globally, the study emphasizes a concerning trend in marine ecosystems. “These findings deepen our understanding of the frequency and intensity of extreme temperature events beneath the ocean surface and their possible implications,” stated CSIRO researcher Ming Feng.
Marine heatwaves, defined as prolonged periods of elevated ocean temperatures, pose significant threats to marine habitats, leading to devastating impacts on coral reefs and shifts in species distribution. The study asserts that such events are increasingly frequent due to global warming, with potential “catastrophic ecological and socioeconomic impacts.”
Traditionally, research on marine heatwaves has concentrated on surface temperature signals, predominantly derived from satellite observations. However, this latest study underscores the critical need to understand deeper warming phenomena, as they directly affect habitats vital to marine life.
“Extreme temperature events below the sea surface are of greater ecological concern because they affect the habitat of most marine primary producers and consumers,” the study warns.
Additionally, the research sheds light on the role of ocean currents, particularly eddies, as significant drivers of subsurface heatwaves. These eddies can influence acidification, oxygen levels, and nutrient concentrations, further complicating the marine environment.
Improving our understanding of these subsurface marine heatwaves, especially in the context of climate change, is essential for future assessments and predictions. The findings serve as a call to action for more comprehensive monitoring and research into the less visible impacts of warming oceans.
