Ocean current may be a key to understanding climate change

Three years of research in the eastern equatorial Pacific Ocean has led Paul Loubere, a professor of Geology and Environmental Geosciences at Northern Illinois University, to conclude that marine life there is substantially influenced by the equatorial undercurrent, a deep-sea river originating thousands of miles away in the Antarctic Ocean.

“Until now we had assumed that the biological activity of the eastern equatorial Pacific Ocean was influenced by atmospheric conditions, especially the trade winds, but this research shows the probable control of biology through ocean circulation”, Lebere told edie on 3 August. “The picture is therefore not as simple as previously imagined; we think that the biology of the eastern equatorial Pacific Ocean may depend on what happens around Antarctica – an area which is particularly sensitive to global warming. The research demonstrates the existence of a climatic pathway where linking different regions of the earth, in this case the South Pole and the Pacific equator,” he said.

Loubere explained that conditions for examining climate change in the area where the 300 to 400 feet deep current comes to the surface near the Galapagos Islands, hundreds of miles off the coast of Peru, are ideal. This is because there are vast quantities of carbon dioxide in the area due to extensive recirculation of the carbon sink by the equatorial undercurrent and absorption by plankton.

The researcher’s team took hundreds of sediment samples from four seabed locations to reconstruct a record of marine life activity over the past 130,000 years. Loubere found that the biological records, such as levels of productivity, varied greatly, depending on proximity to the undercurrent. “If tropical or atmospheric processes were controlling things, we should have seen the same biological record everywhere,” he said. “The only way to explain that is the influence of the equatorial undercurrent. Where the undercurrent exerts its greatest influence, there’s a distinctly different pattern of biological activity through time.”

Loubere’s research paper ‘Marine control of biological production in the eastern equatorial Pacific Ocean’ was published in the 3 August edition of the journal,Nature.