The Solubility of Biogenic Calcite

海洋化学研究的一个主要重点是确定海洋在地球碳循环中的作用，包括海洋吸收人为二氧化碳的作用。 研究表明，碳酸钙或方解石（CaCO 3）在海洋中的溶解是CO2中和的重要机制。 然而，最近的数据表明，生物方解石和无机沉淀方解石的溶解度可能存在差异。 鉴于方解石溶解度值在评估拟议的溶解机制（底层水欠饱和与代谢酸添加）和开发溶解动力学模型方面发挥的重要作用，伍兹霍尔海洋研究所的一名科学家计划通过新的实验重新评估方解石溶解度。 具体而言，将进行以下实验：（1）测量无机沉淀方解石的溶解度，（2）测量块状有孔虫方解石和覆盖溶解敏感性范围的单种浮游有孔虫，（3）测量方解石的物理和化学性质;（4）在生物方解石溶解度的新研究中确定有机涂层对方解石与海水平衡的影响。 这项研究的结果将用于重新定义参数，以纳入海洋碳吸收的长期模型。至于更广泛的影响，研究结果将纳入本科和研究生课程的讲座。 预计暑期研究生将在项目的头两年参加方解石溶解度研究。 此外，高中学生将被纳入研究，以获得样品制备和有孔虫采摘程序的经验。

A primary focus of research in marine chemistry involves defining the role of the oceans in the earth's carbon cycle, including the role of oceanic uptake of anthropogenic CO2. Research has shown that calcium carbonate, or calcite (CaCO3), dissolution in the ocean is a significant mechanism for CO2 neutralization. However, recent data has implied that differences in the solubility of biogenic calcite and inorganically precipitated calcite may exist. Given the important role played by the value of calcite solubility in assessing the proposed mechanisms of dissolution (bottom water undersaturation vs. metabolic acid addition) and in developing kinetic models of dissolution, a scientist from Woods Hole Oceanographic Institution plans to re-evaluate calcite solubility with new experiments. Specifically, the following experiments would be carried out: (1) measure the solubility of inorganically precipitated calcite, (2) measure both bulk foraminiferal calcite and individual species of planktonic foraminifera covering a range of dissolution susceptibility, (3) measure the physical and chemical properties of calcite; and (4) determine the effect of organic coatings on the equilibration of calcite with seawater in a new study of the solubility of biogenic calcite. Results from this study would be used to redefine parameters for inclusion into long term models of carbon uptake in the oceansAs regards broader impacts, results from the research would be incorporated into lectures for undergraduate and graduate courses. It is anticipated that summer student fellows would participate in the calcite solubility studies during the first two years of the project. In addition, high school students would be included in the study to get experience with sample preparation and foraminifera picking procedures.