Latitudinal gradient in the respiration quotient and the implications for ocean oxygen availability
Latitudinal gradient in the respiration quotient and the implications for ocean oxygen availability
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呼吸商的纬度梯度及其对海洋氧气可用性的影响
DOI：
10.1073/pnas.2004986117
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Martiny, Adam C.
中科院分区：
文献类型：
--
作者：
Moreno, Allison R.;Garcia, Catherine A.;Larkin, Alyse A.;Lee, Jenna A.;Wang, Wei-Lei;Moore, J. Keith;Primeau, Francois W.;Martiny, Adam C.
气候驱动的海洋氧气枯竭严重影响全球碳和营养循环以及许多动物物种的生存。预测海洋含氧量变化的主要不确定性之一是与生物泵相关的生物呼吸需求的调节。从雷德菲尔德比率得出，呼吸过程中消耗的氧与有机碳的摩尔比(即呼吸商)一直被假定为恒定，但很少被测量到。利用预测的地球系统模式，我们发现呼吸商从1.0增加0.1导致全球氧气减少2.3%，低氧区大幅扩张，额外的水柱反硝化38Tg N/y，以及海洋中固定的氮和碳的产生的损失。然后，我们介绍了使用太平洋子午线横跨所有主要表面生物群类型的直接化学测量。观测值与温度呈正相关，区域平均值与红场比例差异较大。最后，一个受营养物质、氧和碳浓度约束的独立全球逆模型分析支持出口有机物中的正温度依赖关系。我们提供了证据，反对有机碳的呼吸和氧气消耗之间存在静态生物学联系的普遍假设。此外，模型模拟表明，呼吸商的变化将影响多个生物地球化学循环，未来的变暖可能会导致比之前预期更强烈的脱氧作用。
Climate-driven depletion of ocean oxygen strongly impacts the global cycles of carbon and nutrients as well as the survival of many animal species. One of the main uncertainties in predicting changes to marine oxygen levels is the regulation of the biological respiration demand associated with the biological pump. Derived from the Redfield ratio, the molar ratio of oxygen to organic carbon consumed during respiration (i.e., the respiration quotient,) is consistently assumed constant but rarely, if ever, measured. Using a prognostic Earth system model, we show that a 0.1 increase in the respiration quotient from 1.0 leads to a 2.3% decline in global oxygen, a large expansion of low-oxygen zones, additional water column denitrification of 38 Tg N/y, and the loss of fixed nitrogen and carbon production in the ocean. We then present direct chemical measurements ofusing a Pacific Ocean meridional transect crossing all major surface biome types. The observedhas a positive correlation with temperature, and regional mean values differ significantly from Redfield proportions. Finally, an independent global inverse model analysis constrained with nutrients, oxygen, and carbon concentrations supports a positive temperature dependence ofin exported organic matter. We provide evidence against the common assumption of a static biological link between the respiration of organic carbon and the consumption of oxygen. Furthermore, the model simulations suggest that a changing respiration quotient will impact multiple biogeochemical cycles and that future warming can lead to more intense deoxygenation than previously anticipated.
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影响因子：
4.2
作者：
Kim, YC;Sasaki, S;Karube, I
通讯作者：
Karube, I
浮游植物的热量含量
DOI：
--
发表时间：
1973
期刊：
影响因子：
--
作者：
T. Platt;B. Irwin
通讯作者：
B. Irwin
海洋再矿化率的纬度变化及其对营养循环的影响
影响因子：
5.2
作者：
Yuan;T. Peng
通讯作者：
T. Peng
影响因子：
3.7
作者：
Finkel ZV;Follows MJ;Liefer JD;Brown CM;Benner I;Irwin AJ
通讯作者：
Irwin AJ
影响因子：
5.2
作者：
Karl DM;Grabowski E
通讯作者：
Grabowski E