Coral records show ocean thermocline rise with global warming

(Ohio State University) Researchers looking at corals in the western tropical Pacific Ocean have found records linking a profound shift in the depth of the division between warm surface water and colder, deeper water traceable to recent global warming. The finding is the first real evidence supporting what climate modelers have been predicting as the effects of global climate change on the subsurface ocean circulation. The report by researchers from Ohio State University and the University of Toronto was published in the latest online edition of the journal Geophysical Research Letters. “We’re trying to find a way to understand how the warm water in the tropical Pacific has changed in the last century, but more importantly during the last several decades,” said Branwen Williams, who conducted this research while a doctoral student at Ohio State. Williams is now a postdoctoral fellow at the University of Toronto. “The Pacific is really important since it serves as a strong driver and changes in this ocean can have a very strong impact on global climate and oceanography.” … Specifically, the researchers were interested in how the boundary layer between the warmer, shallow water and the colder deeper water — the thermocline — has changed. But directly measuring that over time and across a broad area is impossible. … “Climate modelers looking at how the Pacific might respond to global warming have predicted that the atmospheric patterns in the tropical Pacific would weaken, and if that happened, you would expect the thermocline to get shallower in the western tropical Pacific,” Williams said. “Our data are some of the first proxy data to support what the modelers have been predicting.” …