Ocean Acidification: Collaborative Research: Development of a Compact Instrument for Field Measurements of pH, Total Dissolved Inorganic Carbon, and Total Alkalinity

海洋酸化通常被描述为表层海洋沃茨吸收大气中的二氧化碳所致，对海洋化学和海洋生物具有重要影响。了解这些变化及其后果需要了解海水中溶解的二氧化碳（或碳酸盐）系统的复杂化学性质，以及准确和精确测量碳酸盐系统参数微小变化的能力。这种测量需要专门培训，超出了许多希望从事海洋酸化研究的调查人员的具体专业知识。该项目将支持开发一种便携式自动化仪器，使化学背景有限的调查人员能够收集高质量的碳系统数据，为其海洋酸化研究提供必要的定量背景。该传感器将是一种紧凑、相对低成本、坚固耐用的仪器，旨在从离散样本、岸基站和各种表面平台收集pH值、总溶解无机碳和总碱度数据。该提案的具体目标是开发第三代“多参数无机碳分析仪”（云母III），该分析仪将能够直接测量现场的溶解无机碳（DIC）、总碱度（TA）和pH值。这种多参数传感器将易于操作，高度便携，几乎没有支持基础设施的要求。基础碳系统测量协议先前已在现场使用云母I进行了演示。DIC和pH将构成基本配对，从该配对中将计算其他参数（CO2分压、TA和碳酸根离子浓度）。一个额外的直接测量参数（TA）将允许我们的计算和测量的属性之间的内部热力学一致性的评估。为了在紧凑的仪器内进行TA测量，研究人员将使用一种新的平衡设计作为标准滴定方法的替代方案。通过这种方法，他们计划大大简化仪器，消除对高精度酸计量的要求。最先进的光学、机械和电气设计软件将与实验室和现场测试相结合，使用迭代方法在三年内开发和完善云母III的设计。该项目的预期影响之一-提高对海洋酸化的认识-将通过三种方式实现。首先，通过开发一种技术，大大促进碳系统的测量，该项目将使具有不同目标的研究人员能够在更大的规模上收集和传播碳系统的观测结果。由于拟议的技术完全符合最佳做法协议，因此不同调查的结果在化学背景方面将具有直接可比性。反过来，这将减少观测和解释的不确定性。第二，拟议的活动包括开展海洋酸化讨论和技术示范。这一讨论将在坎特伯雷学校新的库斯托海洋研究中心和彼得堡科学节上向学生们介绍，这两个科学节都在佛罗里达的彼得堡举行。科学节是一项由本地赞助的公众活动，约有12，000至15，000名居民参加。最后，该项目的成果将在同行评审的期刊上发表，并在国家会议上介绍。在这项工作中收集的实地数据和相关元数据将提交给生物和化学海洋学数据管理办公室，该办公室还将把这些数据存档在适当的国家档案设施中。

Ocean acidification, most generally described as resulting from the uptake of atmospheric carbon dioxide by surface ocean waters, has importance consequences for ocean chemistry and for marine organisms. Understanding these changes and their consequences requires an understanding of the complex chemistry of the dissolved carbon dioxide (or carbonate) system in seawater, and the ability to accurately and precisely measure small changes in carbonate system parameters. Such measurements require specialized training and are beyond the specific expertise of many investigators who would like to pursue research related to ocean acidification. This project will support the development of a portable, automated instrument that will enable investigators with limited backgrounds in chemistry to collect high-quality carbon-system data, providing essential quantitative context for their ocean acidification research. The sensor will be a compact, relatively low-cost, robust instrument designed to collect pH, total dissolved inorganic carbon, and total alkalinity data from discrete samples, shore-based stations, and a variety of surface platforms. The specific objective of this proposal is to develop a third-generation "Multi-parameter Inorganic Carbon Analyzer" (MICA III), which will enable straightforward measurements of dissolved inorganic carbon (DIC), total alkalinity (TA), and pH in the field. This multi-parameter sensor will be easy to operate and highly portable, with virtually no supporting infrastructure requirements. The underlying carbon system measurement protocols were previously demonstrated in the field using MICA I. DIC and pH will constitute the fundamental pairing from which other parameters (the partial pressure of CO2, TA, and carbonate ion concentration) will be calculated. An additional directly measured parameter (TA) will allow assessments of internal thermodynamic consistency among our calculated and measured properties. To enable TA measurements within a compact instrument, the investigators will use a novel equilibration design as an alternative to the standard titration methods. With this approach, they plan to substantially simplify the instrument, eliminating requirements for highly precise acid metering. State-of-the-art optical, mechanical, and electrical design software will be employed in conjunction with laboratory and field tests, using an iterative approach to develop and refine the design of MICA III over a three-year period. One of the intended impacts of this project - generating awareness of ocean acidification - will be realized in three ways. First, by developing a technology to substantially facilitate carbon-system measurements, this project will enable researchers with diverse objectives to collect and disseminate observations of the carbon system on a much larger scale. Since the proposed technology is fully consistent with best-practice protocols, results from different investigations will be directly comparable in terms of their chemical context. In turn, this will reduce uncertainties surrounding observations and interpretations. Second, the proposed activities include development of an ocean acidification discussion and technology demonstration. This discussion will be presented to students at the new Cousteau Center for Marine Studies at the Canterbury School and at the St. Petersburg Science Festival, both in St. Petersburg, Florida. The Science Festival is a locally sponsored event for the general public with attendance of about 12,000-15,000 residents. Finally, the results of this project will be published in peer-reviewed journals and presented at national meetings. Field data and associated metadata collected during this effort will be submitted to the Biological and Chemical Oceanography Data Management Office, which will also archive the data in the appropriate national archive facility.