Shallow Calcium Carbonate Cycling in the North Pacific Ocean
Shallow Calcium Carbonate Cycling in the North Pacific Ocean
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DOI：
10.1029/2022gb007388
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发表时间：
2022-05
影响因子：
5.2
通讯作者：
A. Subhas;Sijia Dong;J. Naviaux;N. Rollins;P. Ziveri;W. Gray;J. Rae;Xuewu Liu;R. Byrne;Sang Chen;Christopher S. Moore;Loraine Martell‐Bonet;Z. Steiner;G. Antler;Huanting Hu;A. Lunstrum;Yi Hou;Nathaniel Kemnitz;J. Stutsman;Sven Pallacks;Mathilde Dugenne;P. Quay;W. Berelson;J. Adkins
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文献类型：
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作者：
A. Subhas;Sijia Dong;J. Naviaux;N. Rollins;P. Ziveri;W. Gray;J. Rae;Xuewu Liu;R. Byrne;Sang Chen;Christopher S. Moore;Loraine Martell‐Bonet;Z. Steiner;G. Antler;Huanting Hu;A. Lunstrum;Yi Hou;Nathaniel Kemnitz;J. Stutsman;Sven Pallacks;Mathilde Dugenne;P. Quay;W. Berelson;J. Adkins
生物产生的碳酸钙（CaCO3）在海洋中的循环是全球碳循环的基本组成部分。在这里，我们提出了实验测定原位颗石和有孔虫方解石溶解速率。我们结合联合收割机这些利率与固相通量，溶解示踪剂，和历史数据，以约束在浅北太平洋的碱度循环。颗石藻的原位溶解速率与饱和状态呈非线性关系。溶解速率的所有三个主要的钙化组（球石，有孔虫，文石翼足类）是太慢，以解释两个碳酸钙下沉通量和碱度再生在北太平洋的模式。使用溶解和固相示踪剂的组合，我们记录了方解石过饱和海水中的显著溶解信号。结合环境饱和状态和氧气消耗来驱动CaCO3溶解，同时解释了整个N中固相CaCO3通量分布和碱度再生模式。太平洋盆地。我们不需要援引具有更高溶解度的碳酸盐相的存在。相反，生物矿化和代谢过程密切相关的酸（CO2）和碱（CaCO3）在相同的颗粒，驱动耦合的有机碳和CaCO3的浅层矿化。这些过程之间的联系可能是由于浮游动物摄食和降解颗粒聚集体内微生物好氧呼吸引起的溶解作用的结合而发生的。这些循环的结合是有机碳和无机碳向深海输出的主要过滤器。
The cycling of biologically produced calcium carbonate (CaCO3) in the ocean is a fundamental component of the global carbon cycle. Here, we present experimental determinations of in situ coccolith and foraminiferal calcite dissolution rates. We combine these rates with solid phase fluxes, dissolved tracers, and historical data to constrain the alkalinity cycle in the shallow North Pacific Ocean. The in situ dissolution rates of coccolithophores demonstrate a nonlinear dependence on saturation state. Dissolution rates of all three major calcifying groups (coccoliths, foraminifera, and aragonitic pteropods) are too slow to explain the patterns of both CaCO3 sinking flux and alkalinity regeneration in the North Pacific. Using a combination of dissolved and solid‐phase tracers, we document a significant dissolution signal in seawater supersaturated for calcite. Driving CaCO3 dissolution with a combination of ambient saturation state and oxygen consumption simultaneously explains solid‐phase CaCO3 flux profiles and patterns of alkalinity regeneration across the entire N. Pacific basin. We do not need to invoke the presence of carbonate phases with higher solubilities. Instead, biomineralization and metabolic processes intimately associate the acid (CO2) and the base (CaCO3) in the same particles, driving the coupled shallow remineralization of organic carbon and CaCO3. The linkage of these processes likely occurs through a combination of dissolution due to zooplankton grazing and microbial aerobic respiration within degrading particle aggregates. The coupling of these cycles acts as a major filter on the export of both organic and inorganic carbon to the deep ocean.