Ocean Acidification: Collaborative Research: Investigation of seawater CO2 system thermodynamics under high pCO2 conditions

海洋酸化：合作研究：高 pCO2 条件下海水 CO2 系统热力学研究

• 批准号: 1220110
• 负责人: Robert Byrne
• 金额: $ 65.06万
• 依托单位: University of South Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-15 至 2018-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1220110&HistoricalAwards=false
• 关键词: Ocean; Acidification; Collaborative; Research; Investigation

Assessments of the effects of ocean acidification in a high CO2 world require well-constrained models that interrelate measurable carbon system parameters: total dissolved inorganic carbon (CT) and total alkalinity (AT), CO2 fugacity (fCO2), pH and carbonate ion concentration ([CO3 2-]). Current thermodynamic models that relate CT and AT to fCO2 using carbonic acid dissociation constants (K1' and K2') developed for seawater analyses have been shown to provide good results at current fCO2 values ca. 380 uatm, but break down at the elevated CO2 concentrations (500 uatm) that are likely to occur before the end of this century. Studies of the effects of elevated CO2 on organismal and ecosystem functions require robust thermodynamic models to ensure that results, which occasionally involve measurements of only two system-variables, provide accurate depictions of the investigated system in its entirety. Because accurate predictions of the consequences of ocean acidification are critical to guide management and policy decisions, development of accurate thermodynamic CO2 system models is essential.In this project, researchers at the University of South Florida and SRI International will perform best practices measurements of CT, AT, fCO2 and pH, and subsequently assess the magnitudes of K1', K2' and KB' that produce an internally consistent thermodynamic model of the marine CO2 system. The proposed work is facilitated by (a) the recent development and characterization of purified indicators for precise and accurate seawater pH measurements and (b) the development of accurate borate to salinity ratios that provide an improved account of the contributions of boric acid to the buffer intensity of seawater. The study will include investigations of the AT contributions of uncharacterized seawater protolytes (e.g. from dissolved organic matter) as well as the possible interactions between carbonate and borate ions that may influence CO2 equilibria under high pCO2 conditions. The proposed work will additionally be promoted by the recent development of UV spectrometric procedures for direct measurements of carbonate ion concentrations in seawater.Broader Impacts: The OCB Ocean Acidification Principal Investigator Workshop Report (2011) identified a near-term need to "determine the consequences of large pH change on the carbonate system; as pH shifts the carbonate system may respond in ways different from the range we customarily measure". Since interpretation of the results of CO2 system perturbation experiments depend on accurate knowledge of the carbon system parameters under which the experiments were performed, development of improved carbon system equilibrium relationships, especially at high CO2 levels, is vitally important to the study of ocean acidification.Graduate and undergraduate students involved in the project will benefit from learning carbon system best practices as well as obtaining a comprehensive understanding of CO2 system thermodynamics. The field component will provide hands-on experience in at sea measurements and statistical analysis of CO2 system relationships. Furthermore, we intend to develop an ocean acidification classroom and laboratory module that will be taught at a local high school serving an ethnically-diverse student population. The lesson plans developed during this activity will be presented to teachers at the annual District-wide Training for High School Science/Math for Pinellas County schools.

评估海洋酸化在高二氧化碳世界中的影响需要构成良好的模型，以相互关联可测量的碳系统参数：总溶解的无机碳（CT）和总碱度（AT），二氧化碳（FCO2），pH和碳酸盐离子浓度（[CO3 2-]）。目前，使用碳酸解离常数（K1'和K2'）与海水分析开发的当前热力学模型与FCO2相关联，已证明可以在当前FCO2值Ca中提供良好的效果。 380 UATM，但在本世纪末之前可能发生的二氧化碳浓度（500 UATM）分解。对二氧化碳对生物和生态系统功能的影响的研究需要强大的热力学模型，以确保结果（偶尔涉及两个系统变量的测量）的结果提供了整体上对研究系统的准确描述。 Because accurate predictions of the consequences of ocean acidification are critical to guide management and policy decisions, development of accurate thermodynamic CO2 system models is essential.In this project, researchers at the University of South Florida and SRI International will perform best practices measurements of CT, AT, fCO2 and pH, and subsequently assess the magnitudes of K1', K2' and KB' that produce an internally consistent thermodynamic model of the marine CO2 system. （a）纯化的指标的最新发展和表征为精确，准确的海水pH测量值以及（b）精确硼酸盐与盐度比率的发展提供了促进的工作，从而改善了硼酸对海水缓冲强度的贡献。该研究将包括对未表征的海水原产力（例如溶解有机物）的AT贡献以及在高PCO2条件下可能影响CO2平衡的碳酸盐离子和碳酸盐离子之间可能的相互作用。拟议的工作还将通过最近开发的紫外线光谱程序来促进，以直接测量海水中的碳酸盐离子浓度。Broader的影响：OCB海洋酸化主要研究者研讨会（2011）的报道（2011年）确定了“确定对碳酸盐系统的大量pH变化的后果；根据pH衡量碳酸盐系统的范围可能会响应碳酸盐系统的范围不同。由于对CO2系统摄动实验的结果的解释取决于对实验进行实验参数的准确了解，因此在高二氧化碳水平上，改善了碳系统平衡关系的发展，尤其是在高二氧化碳水平上，对海洋酸化的研究至关重要。对海洋酸化的研究至关重要。涉及的级别的学生将受益于研究碳体系的最佳习惯，从而使coy的最佳实践受益匪浅。现场组件将在海上测量和CO2系统关系的统计分析方面提供动手经验。此外，我们打算开发一个海洋酸化课堂和实验室模块，该模块将在当地的高中教授，为种族多样的学生人数提供服务。在这项活动期间制定的课程计划将在年度范围内为Pinellas县学校的高中科学/数学培训提供给教师。