Decline in global oceanic oxygen content during the past five decades
Decline in global oceanic oxygen content during the past five decades
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DOI：
10.1038/nature21399
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发表时间：
2017-02-16
期刊：
影响因子：
64.8
通讯作者：
Visbeck, Martin
中科院分区：
文献类型：
--
作者：
Schmidtko, Sunke;Stramma, Lothar;Visbeck, Martin
海洋模型预测，到2100年，全球海洋的溶解氧存量将下降1%至7%，这是由变暖引起的氧溶解度下降和深海通风减少共同造成的（1、2）。据认为，海洋含氧量的这种下降可能会影响海洋养分循环和海洋生境，对渔业和沿海经济产生潜在的有害后果（3-6）。区域观测数据表明，在全球海洋的大多数区域，海洋溶解氧浓度持续下降（1、7 -10），少数几个有限区域报告的浓度有所上升，各研究报告的情况各不相同（1、10）。先前试图解决全球范围内溶解氧浓度变化的工作报告称，根据20世纪70年代和90年代的数据比较，在100米至1,000米深度之间，全球氧损失为每十年550 +/- 130万亿摩尔（10（12）mol）（10）。在这里，我们通过分析溶解氧和过去50年来完整海洋水柱的支持数据，对整个海洋氧库存进行定量评估。我们发现，自1960年以来，全球海洋氧含量为227.4 +/- 1.1 petamoles（10（15）mol），下降了2%以上（4.8 +/- 2.1 petamoles），不同海洋盆地和不同深度的氧损失变化很大。我们认为，在上层水柱的变化主要是由于变暖引起的溶解度和生物消耗减少。海洋深处的变化可能源于盆地尺度的数十年变化、海洋翻转减缓和生物消耗的潜在增加（11、12）。
Ocean models predict a decline in the dissolved oxygen inventory of the global ocean of one to seven per cent by the year 2100, caused by a combination of a warming-induced decline in oxygen solubility and reduced ventilation of the deep ocean(1,2). It is thought that such a decline in the oceanic oxygen content could affect ocean nutrient cycles and the marine habitat, with potentially detrimental consequences for fisheries and coastal economies(3-6). Regional observational data indicate a continuous decrease in oceanic dissolved oxygen concentrations in most regions of the global ocean(1,7-10), with an increase reported in a few limited areas, varying by study(1,10). Prior work attempting to resolve variations in dissolved oxygen concentrations at the global scale reported a global oxygen loss of 550 +/- 130 teramoles (10(12) mol) per decade between 100 and 1,000 metres depth based on a comparison of data from the 1970s and 1990s(10). Here we provide a quantitative assessment of the entire ocean oxygen inventory by analysing dissolved oxygen and supporting data for the complete oceanic water column over the past 50 years. We find that the global oceanic oxygen content of 227.4 +/- 1.1 petamoles (10(15) mol) has decreased by more than two per cent (4.8 +/- 2.1 petamoles) since 1960, with large variations in oxygen loss in different ocean basins and at different depths. We suggest that changes in the upper water column are mostly due to a warming-induced decrease in solubility and biological consumption. Changes in the deeper ocean may have their origin in basin-scale multi-decadal variability, oceanic overturning slow-down and a potential increase in biological consumption(11,12).