Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program in Oceanography, Woods Hole, MA 02543, USA.
Science. 2012 Feb 3;335(6068):557-61. doi: 10.1126/science.1208163. Epub 2011 Dec 15.
Changes in the upwelling and degassing of carbon from the Southern Ocean form one of the leading hypotheses for the cause of glacial-interglacial changes in atmospheric carbon dioxide. We present a 25,000-year-long Southern Ocean radiocarbon record reconstructed from deep-sea corals, which shows radiocarbon-depleted waters during the glacial period and through the early deglaciation. This depletion and associated deep stratification disappeared by ~14.6 ka (thousand years ago), consistent with the transfer of carbon from the deep ocean to the surface ocean and atmosphere via a Southern Ocean ventilation event. Given this evidence for carbon exchange in the Southern Ocean, we show that existing deep-ocean radiocarbon records from the glacial period are sufficiently depleted to explain the ~190 per mil drop in atmospheric radiocarbon between ~17 and 14.5 ka.
海洋上升流和碳脱气的变化是导致大气二氧化碳在冰期-间冰期变化的主要假说之一。我们从深海珊瑚中重建了一个长达 25000 年的南大洋放射性碳记录，该记录显示在冰期和早期冰消期间存在放射性碳亏损的水。这种亏损和相关的深层分层在约 14.6 千年前消失，与通过南大洋通风事件将碳从深海转移到海洋表面和大气中的情况一致。鉴于南大洋碳交换的这一证据，我们表明，现有来自冰期的深海放射性碳记录已经严重亏损，足以解释大气放射性碳在~17 到 14.5 千年前下降了约 190 个千分点。
