Southern Ocean carbon sink has renewed strength

(Press-News.org) This news release is available in Japanese.

The Southern Ocean has increased its uptake of atmospheric carbon dioxide again, after showing signs of slowing uptake in the 1990s, according to a new report from Peter Landschützer and colleagues. The Southern Ocean is a huge player in carbon sequestration, accounting for up to 40% of oceanic uptake of atmospheric carbon dioxide. When earlier studies showed the Southern Ocean's carbon sink weakening, the findings raised concerns that the planet might lose a powerful way to remove the growing amounts of carbon dioxide emitted by human activity that are driving global climate change. Although it is welcome news that the Southern Ocean can sop up more carbon dioxide than it seemed it would, the researchers say that the new findings also illustrate how variable the carbon sink can be over time. Landschützer and colleagues analyzed a global data set of the differences between atmospheric and ocean carbon dioxide concentrations that included 2.6 million observations from the Southern Ocean over the course of 30 years. Their analyses suggest that the Southern Ocean carbon sink was weaker than normal from the early 1980s until about 2002. After that, the sink began to grow stronger again due to a variety of factors, including differences in sea surface temperature and the amount of dissolved inorganic carbon, operating over several sectors of the Southern Ocean. S. E. Mikaloff Fletcher discusses the results in a related Perspective.

INFORMATION:

Article #11: "The reinvigoration of the Southern Ocean carbon sink," by P. Landschützer; N. Gruber; F.A. Haumann at ETH Zürich in Zürich, Switzerland; C. Rödenbeck at Max Planck Institute for Biogeochemistry in Jena, Germany; D.C.E. Bakker at University of East Anglia in Norwich, UK; S. van Heuven; M. Hoppema at Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research in Bremerhaven, Germany; N. Metzl at Sorbonne Universités in Paris, France; N. Metzl at Université Pierre et Marie Curie - UMPC in Paris, France; N. Metzl at CNRS in Paris, France; C. Sweeney at National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory in Boulder, CO; T. Takahashi at Lamont-Doherty Earth Observatory of Columbia University in Palisades, NY; B. Tilbrook at Commonwealth Scientific and Industrial Research Organisation and Antarctic Climate and Ecosystems Cooperative Research Centre in Hobart, TAS, Australia; R. Wanninkhof at Atlantic Oceanographic and Meteorological Laboratory of NOAA in Miami, FL; S. van Heuven at Royal Netherlands Institute of Sea Research (NIOZ) in Texel, Netherlands.

Article #3: "An increasing carbon sink?" by S.E. Mikaloff Fletcher at National Institute of Water and Atmospheric Research (NIWA) in Wellington, New Zealand.