Collaborative Research: CaCO3 Dissolution in the North Pacific Ocean: Comparison of Lab and Field Rates with Biogenic and Abiogenic Carbonates

海洋酸化（OA）是由于海洋从大气中吸收的人为二氧化碳（CO2）增加而导致的海水pH值下降。 这种吸收在海洋环境中的影响被碳酸钙（CaCO 3）溶解为钙和碳酸根离子，使碳酸根离子结合导致pH值降低的游离氢离子所减弱。来自南加州大学和加州理工学院的研究人员开发了一种新方法，用于确定在实验室和现场环境中工作的碳酸盐溶解速率。 使用这种技术的初步数据表明，在实验室和现场获得的测量速率之间存在明显差异。 至关重要的是，实验室和现场测量标准化，以便能够准确地研究和比较溶出速率研究。因此，研究人员将进行广泛的实地调查和实验室，以弥合这些溶解速率测量之间的差距。 结果将是广泛有用的海洋化学界，特别是建模，希望研究海洋碳酸盐化学的任何方面，以及古海洋学家使用碳酸盐材料来研究过去的海洋条件。 研究生将由研究人员共同指导，南加州大学？南加州大学的青年研究员计划将允许研究人员参与当地的高中生。南加州大学国际关系学院的学生将参与该项目，不仅获得科学经验，还将学习科学的政策方面。碳酸钙（CaCO 3）溶解有助于减轻海洋酸化（OA）的影响，是海洋中的一个关键因素？的碱度平衡。研究人员最近开发了一种新的示踪方法，可以在实验室和现场监测碳酸盐溶解速率。该方法跟踪13 C从标记固体到海水的转移。使用这种方法在理解CaCO 3溶解动力学的控制方面取得了突破，但它也揭示了在实验室和现场进行的测量并不完全一致。能够将这两种测量结果关联起来，以便能够充分研究和理解CaCO 3溶解的动力学，这一点至关重要。因此，研究人员将扩展他们以前的工作，将实验室中的测量结果与海洋中的测量结果标准化。具有碳酸盐饱和状态梯度的北太平洋将用于现场研究，基于实验室的实验将使研究人员能够限制压力，溶解无机碳/碱度比和磷酸盐浓度等变量。这项研究将进一步了解OA，控制碳酸盐溶解的机制，以及海洋如何调节其碱度预算。

Ocean acidification (OA) is the decrease in seawater pH due to increased oceanic uptake of anthropogenic carbon dioxide (CO2) from the atmosphere. The impact of this uptake in the marine environment is lessened by the dissolution of calcium carbonate (CaCO3) to calcium and carbonate ions, allowing carbonate ions to bind free hydrogen ions that cause the decrease in pH. Researchers from the University of Southern California and California Institute of Technology have developed a new method for determining carbonate dissolution rates that work in both laboratory and field settings. Preliminary data using this technique has revealed a distinct difference in measured rates between those obtained in the laboratory and those in the field. It is crucial that laboratory and field measurements be standardized to be able to accurately study and compare dissolution rate studies. As such, the researchers will perform extensive fieldwork and laboratory to bridge the gap between these dissolution rate measurements. Results will be widely useful to the ocean chemistry community, especially modelers, wishing to study any aspect of ocean carbonate chemistry, as well as paleoceanographers using carbonate material to study past ocean conditions. Graduate students will be co-mentored by the researchers, and the University of Southern California?s (USC) Young Researcher Program will allow the researchers to involve local high school students. USC International Relations students will be involved in the project, not only gaining scientific experience, but also will learn the policy aspect of the science.Calcium carbonate (CaCO3) dissolution helps to mitigate the effects of ocean acidification (OA) and is a key factor in the ocean?s alkalinity balance. The researchers have recently developed a novel tracer methodology which can monitor carbonate dissolution rates in both the lab and field. This method traces the transfer of 13C from labeled solids to seawater. Using this method has led to breakthroughs in understanding the controls of CaCO3 dissolution kinetics, but it has also revealed that the measurements made in a lab and in the field are not entirely in line. It is crucial to be able to correlate these two measurements to be able to fully study and understand the dynamics of CaCO3 dissolution. Therefore, the researchers will extend their previous work to standardize the results of measurements in the lab with those in the ocean. The North Pacific Ocean with a gradient in carbonate saturation states will be used for the field study, and lab-based experiments will allow the researchers to constrain variables such as pressure, the dissolved inorganic carbon/alkalinity ratio, and concentrations of phosphate. This research will further understanding of OA, the mechanisms controlling carbonate dissolution, and how the ocean modulates its alkalinity budget.