US GEOTRACES OCE: Measuring the distribution of stable carbon isotopes and estimating organic matter export rates

美国 GEOTRACES OCE：测量稳定碳同位素的分布并估算有机物出口率

• 批准号: 2048523
• 负责人: Paul Quay
• 金额: $ 55.39万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2048523&HistoricalAwards=false
• 关键词: US; GEOTRACES; OCE; Measuring; distribution

The goal of this project is to measure the concentration of the rare isotope of carbon (13C) present in the carbon dioxide (CO2) molecules dissolved in seawater of the South Pacific Ocean. 13C atoms make up only 1% of the carbon atoms on earth whereas atoms with the common carbon isotope (12C) make up 99% of the carbon atoms. Variations in the concentration of 13C atoms are represented relative to the concentration of 12C atoms and expressed as the 13C/12C ratio. The utility of measuring spatial variations in the 13C/12C of CO2 in the ocean results from two observations. First, during photosynthesis the 13C/12C of the plant (phytoplankton in the ocean) is distinctly different from the 13C/12C of CO2 consumed during photosynthesis. Second, the 13C/12C of CO2 molecules produced during the combustion of fossil fuels (coal, oil, natural gas) is measurably different from the 13C/12C of CO2 in the atmosphere and ocean. As a result, measuring the spatial variations of 13C/12C of CO2 in the ocean can be used to estimate variations in the rate of photosynthesis and the rate at which CO2 produced by fossil fuel combustion is being adsorbed by the ocean. Estimating variations in these two rates are goals of this project. The 13C/12C of CO2 in the ocean depends in large part on the rates of photosynthesis and respiration, which results in spatial covariations in the 13C/12C of CO2, concentrations of primary nutrients (nitrate and phosphate) and trace elements that are used by phytoplankton (e.g., Cadmium). In this project, the planned measurements of the 13C/12C of CO2, nutrients and trace elements during the GEOTRACES GP17 cruise will be used to determine how the north-south variations in biological productivity (photosynthesis and respiration), elemental composition of sinking particles and water mass mixing control the regional variations in the 13C/12C of CO2, nutrients and bioactive trace element distributions in the S. Pacific Ocean. An improved understanding of the biological, chemical and physical processes that control spatial variations of 13C/12C of CO2, bioactive trace elements and nutrient distributions in the modern ocean will improve our ability to use 13C/12C and trace elements measurements on CaCO3 preserved in the sedimentary record to reconstruct past changes in the ocean circulation and CO2 cycling in the paleo ocean. The project will involve undergraduate students in the research activities and carry out public outreach through University of Washington, Program on Climate Change (PCC).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目的目标是测量南太平洋海水中溶解的二氧化碳 (CO2) 分子中稀有碳同位素 (13C) 的浓度。 13C 原子仅占地球上碳原子的 1%，而具有常见碳同位素 (12C) 的原子则占碳原子的 99%。 13C原子浓度的变化相对于12C原子浓度表示并表示为13C/12C比率。 测量海洋中 CO2 13C/12C 空间变化的效用源自两次观测。 首先，在光合作用过程中，植物（海洋中的浮游植物）的 13C/12C 与光合作用过程中消耗的 CO2 的 13C/12C 明显不同。 其次，化石燃料（煤、石油、天然气）燃烧过程中产生的 CO2 分子的 13C/12C 与大气和海洋中 CO2 的 13C/12C 有明显不同。 因此，测量海洋中二氧化碳 13C/12C 的空间变化可用于估计光合作用速率的变化以及化石燃料燃烧产生的二氧化碳被海洋吸收的速率的变化。 估计这两个速率的变化是该项目的目标。海洋中 CO2 的 13C/12C 在很大程度上取决于光合作用和呼吸的速率，这导致 CO2 的 13C/12C、主要营养物（硝酸盐和磷酸盐）浓度以及生物利用的微量元素的空间协变。浮游植物（例如镉）。在该项目中，计划在 GEOTRACES GP17 巡航期间测量 13C/12C 二氧化碳、营养物和微量元素，将用于确定生物生产力（光合作用和呼吸）、下沉颗粒的元素组成和水团混合控制着南太平洋13C/12C CO2、营养物和生物活性微量元素分布的区域变化。更好地了解控制现代海洋中 CO2、生物活性微量元素和营养物分布的 13C/12C 空间变化的生物、化学和物理过程，将提高我们对保存在海洋中的 CaCO3 使用 13C/12C 和微量元素测量的能力沉积记录重建古海洋海洋环流和二氧化碳循环的过去变化。该项目将让本科生参与研究活动，并通过华盛顿大学气候变化项目 (PCC) 开展公共宣传。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和更广泛的评估进行评估，认为值得支持。影响审查标准。