Subarctic Pacific evidence for a glacial deepening of the oceanic respired carbon pool
Subarctic Pacific evidence for a glacial deepening of the oceanic respired carbon pool
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DOI：
10.1016/j.epsl.2008.10.017
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发表时间：
2009-01-15
影响因子：
5.3
通讯作者：
Thierstein, H. R.
中科院分区：
文献类型：
--
作者：
Jaccard, S. L.;Galbraith, E. D.;Thierstein, H. R.
对底栖有孔虫Cd：Ca(Cd/Ca)的测量表明，北太平洋深海磷酸盐(PO(4))浓度的冰期-间冰期变化很小，一些工作人员认为这是生物泵没有在冰川深处储存更多碳的迹象。在这里，我们展示了大洋钻探计划(ODP882)站点882(西北亚北极太平洋，水深3244米)的沉积氧化还原敏感痕量金属记录，以推断北太平洋深层氧合作用的变化，从而推断过去150,000年来碳的呼吸储存。作为过去有机碳输出的指标，这些观测与生物源的钡和蛋白石测量相补充，以区分深水氧浓度和沉积有机碳呼吸对沉积物氧化还原状态的影响。我们的结果表明，在冰盛期，虽然没有缺氧，但OXEN中的深亚北极太平洋水团被删除了。我们将我们的结果与现有的海底有孔虫Cd/Ca进行了协调，引用了深海营养物质清单中预先形成的部分的减少，而不是重新矿化。这一变化将对应于太平洋深海呼吸碳储存的增加，这将通过将二氧化碳从大气中隔离出来并通过深海的瞬时溶解事件增加海洋碱度来降低大气二氧化碳(CO(2))。北太平洋数据所显示的预制营养物的变化幅度将是观测到的冰川大气PCO减少的主要原因(2)。(C)2008爱思唯尔B.V.保留所有权利。
Measurements of benthic foraminiferal cadmium:calcium (Cd/Ca) have indicated that the glacial-interglacial change in deep North Pacific phosphate (PO(4)) concentration was minimal which has been taken by some, workers as a sign that the biological pump did not store more carbon in the deep glacial ocean. Here we present sedimentary redox-sensitive trace metal records from Ocean Drilling Program (ODP) Site 882 (NW subarctic Pacific, water depth 3244 m) to make inferences about changes in deep North Pacific oxygenation and thus respired carbon storage - over the past 150,000 yr. These observations are complemented with biogenic barium and opal measurements as indicators for past organic carbon export to separate the influences of deep-water oxygen concentration and sedimentary organic carbon respiration on the redox state of the sediment. Our results suggest that the deep subarctic Pacific water mass was deleted in ox en during glacial maxima, though it was not anoxic. We reconcile our results with the existing benthic foraminiferal Cd/Ca by invoking a decrease in the fraction of the deep ocean nutrient inventory that was preformed, rather than remineralized. This change would have corresponded to an increase in the deep Pacific storage of respired carbon, which Would have lowered atmospheric carbon dioxide (CO(2)) by sequestering CO(2) away from the atmosphere and by increasing ocean alkalinity through a transient dissolution event in the deep sea. The magnitude of change in preformed nutrients suggested by the North Pacific data Would have accounted for a majority of the observed decrease in glacial atmospheric PCO(2). (c) 2008 Elsevier B.V. All rights reserved.