Global warming is causing temperature across the globe to rise. The rate has increased in the last decades, with climatologists warning of the extreme effects that the mankind has to experience. The scientists have also been tracking temperature data streaming in from ocean surfaces. But in a shocking discovery, they have found that marine heatwaves can unfold deep underwater too, even if there is no detectable warming signal above. The discovery is based on new modelling led by researchers at the US National Oceanic and Atmospheric Administration (NOAA).
The research detailing the underwater heatwave has been published in Nature Communications.
"This is the first time we've been able to really dive deeper and assess how these extreme events unfold along shallow seafloors," the study's lead author Dillon Amaya, a climate scientist with NOAA's Physical Science Laboratory, is quoted as saying by Science Direct.
It is based on the analysis of underwater temperature of continental shelf waters surrounding North America.
"This research is particularly significant as the oceans continue to warm, not only at the surface but also at depth, impacting marine habitat along continental shelves," said co-author Clara Deser.
The scientists found that marine heatwaves can be more intense and last longer than hot spells at the ocean surface, though it varies from coast to coast.
The simulations found that bottom marine heatwave and surface marine heatwave tend to occur at the same time in shallow regions where surface and bottom waters mingle. But in deeper parts of the oceans, bottom marine heatwaves can develop without any indication of warming at the surface.
Temperature spikes along the seafloor ranged from half a degree Celsius up to 5 degrees Celsius, the research further found.
According to NOAA, marine heatwaves are periods of persistent anomalously warm ocean temperatures, which can have significant impacts on marine life as well as coastal communities and economies.
According to data, about 90 per cent of the excess heat from global warming has been absorbed by the ocean, which has warmed by about 1.5 degrees Celsius over the past century.