Science Alert March 25, 2021
An international team of researchers (Australia, UK, Germany, France, USA – Carnegie Mellon University) used global temperature and salinity observations obtained between 1970 and 2018 with a focus on the summer months. They found that the barrier layer separating the ocean surface and the deep layers had strengthened world-wide at a much larger rate than previously thought and contrary to their expectations, winds strengthened by climate change had also acted to deepen the ocean surface layer by five to 10 metres per decade over the last half century. The oceans play a crucial role in mitigating the effects of climate change by absorbing around a quarter of man-made CO2 and soaking up more than 90 percent of the heat generated by greenhouse gases, according to the IPCC. Increased rainfall and melting of the Greenland ice sheet have increased the freshwater in the upper ocean, disrupting the normal cycle that carries warm, salty surface water northwards from the equator and sends low-salinity deep water back southwards. The work calls for reconsideration of the drivers of ongoing shifts in marine primary production and reveals stark changes in the world’s upper ocean over the past five decades…read more. TECHNICAL ARTICLE
The three-layer structure of the world ocean. CEDIT: Nature volume 591, pages592–598(2021)