Vertical motions associated with this current have been responsible for transporting a substantial fraction of the anthropogenic carbon dioxide emissions from the atmosphere to the deep ocean, thereby effectively damping the rate of global warming.
Investigations in this key region of the world ocean have been hampered by a sparse database due to the logistical challenges for ship based expeditions in the high-latitude Southern Ocean.
“In our study we used data obtained by the international Argo Programme”, explains Prof. Claus Böning from the Leibniz Institute of Marine Sciences (IFM-GEOMAR) in Kiel, Germany. Argo is a system of currently 3000 autonomous free-floating robotic systems which are surveying the world ocean. Every 10 days these buoys measure temperature and salinity profiles over the upper 2000 meters. These measurements are transmitted to land stations via satellite. “For this study about 52,000 profiles of more than 600 Argo-drifters in the Southern Ocean were used and compared with historic ship measurements”, explains oceanographer Astrid Dispert from IFM-GEOMAR. For this analysis the extensive archives of the Australian marine research centre in Hobart, Tasmania were also used.
As expected, the observations in the subpolar ocean demonstrate an increase of water temperature and a decrease in salinity at the same time. Nevertheless, in contradiction to the simulations of various climate models the data show no significant changes in water transport. “Our results point to one important thing: Eddies which are currently not resolved in climate models might be the key process in controlling the transport of the ACC”, Prof. Böning explains. Hence, his conclusion is that investigations with high-resolution ocean models are required to test this hypothesis. “Of course, besides the simulations we also need further observations”, adds Prof. Martin Visbeck (IFM-GEOMAR). “Thanks to the international Argo observations programme we now have continuously access to data from a worldwide network of more than 3000 profiling-drifters. This is a quantum leap in the field of ocean observations, which, together with high resolution modelling gives us new insights about long-term changes in the ocean.“
Further investigations have to show whether the results are robust. If confirmed, this would in one way be good news: Until now the Southern Ocean is the biggest oceanic sink for anthropogenic carbon dioxide and therefore a crucial regulator for the atmospheric carbon dioxide concentration. Climate models predicted a severe reduction in the southern ocean carbon dioxide uptake due to wind-forced changes in the current fields. Now high-resolution models are needed to assess the role of the hitherto unresolved ocean eddies in the Southern Ocean’s response to the progressive changes in the atmospheric conditions.Scientific Paper:
Andreas Villwock | alfa
Despite government claims, orangutan populations have not increased. Call for better monitoring
06.11.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Increasing frequency of ocean storms could alter kelp forest ecosystems
30.10.2018 | University of Virginia
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
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Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
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Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
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On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
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