U.S. GEOTRACES North Atlantic Section: CFC and SF6 Measurements

美国 GEOTRACES 北大西洋部分：CFC 和 SF6 测量

• 批准号: 0928612
• 负责人: William Smethie
• 金额: $ 26.02万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-12-01 至 2012-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0928612&HistoricalAwards=false
• 关键词: U.S.; GEOTRACES; North; Atlantic; Section

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The objectives of the GEOTRACES program are: 1) to determine the global distributions of selected trace elements and isotopes and evaluate the sources, sinks and internal cycling of these species to better understand the physical, chemical and biological processes regulating their distributions, 2) to develop an understanding of the processes involved in oceanic trace element cycles sufficiently well that the response of these cycles to global change can be predicted and their impact on the carbon cycle and climate understood, and 3) to understand the processes that control the concentrations of geochemical species used for proxies of the past environment, both in the water column and in the substrates that reflect the water column. Understanding how the physical processes of advection, mixing, and water mass formation affect the distributions of trace elements and isotopes is critical to meeting these objectives. The evolving CFC and SF6 distributions in the ocean provide strong constraints on these processes. CFCs have been measured extensively in the global ocean for the past two and a half decades as part of several large scale oceanographic programs (e.g. SAVE, WOCE, CLIVAR) as well as many smaller programs and SF6 has become a standard measurement on the CLIVAR cruises. Measurement of CFCs and SF6 on the GEOTRACES program places the GEOTRACES data in the context of large scale ventilation patterns established by CFC/SF6 measurements on these cruises. In this project, researchers at the Lamont-Dougherty Earth Observatory of Columbia University will measure the CFC-11, CFC-12 and SF6 distributions along the US GEOTRACES North Atlantic cruise track. They will use these data to identify the most recently ventilated cores of the North Atlantic water masses, to estimate transit times of these water masses from their source regions, and to estimate oxygen consumption rates and rates of production or decomposition of selected trace elements measured on this program using the transit time information. Broader Impacts: In addition to providing information on ventilation and transit times for the GEOTRACES project, the CFC and SF6 data collected on this cruise will also expand the transient tracer data base for the North Atlantic Ocean. The data will be disseminated widely to the research community following NSF guidelines. Several CLIVAR cruises to the North Atlantic are planned for the 2010 - 2012 time period, and the GEOTRACES cruise will increase the coverage for CFCs and SF6. This database of the temporally evolving CFC and SF6 concentrations in the North Atlantic Ocean is used in studies of the earth's climate and the ocean's role in the earth's climate and the global CO2 cycle. It is used to validate models of ocean circulation and to quantify the uptake and storage of anthropogenic CO2 in the ocean.

该奖项由《2009年美国复苏和再投资法案》(公法111-5)资助。该计划的目标是：1)确定选定的微量元素和同位素的全球分布，并评估这些物种的源、汇和内部循环，以更好地了解调节它们分布的物理、化学和生物过程；2)充分了解海洋微量元素循环所涉及的过程，以便能够预测这些循环对全球变化的反应，并了解它们对碳循环和气候的影响；以及3)了解控制过去环境替代物所用的地球化学物种浓度的过程。在水柱和反映水柱的基质中都是如此。了解平流、混合和水团形成的物理过程如何影响微量元素和同位素的分布对于实现这些目标至关重要。海洋中不断变化的氯氟化碳和六氟化硫分布对这些过程构成了强有力的限制。在过去的25年里，作为几个大型海洋学项目(如SAVE、WOCE、CLIVAR)以及许多较小项目的一部分，CFCs在全球海洋中得到了广泛的测量，SF6已成为CLIVAR邮轮的标准测量方法。在GEOTRACES计划上对CFCs和SF6的测量将GEOTRACES的数据放在这些巡航上通过CFCs/SF6测量建立的大范围通风模式的背景下。在这个项目中，哥伦比亚大学Lamont-Dougherty地球天文台的研究人员将测量美国GEOTRACES北大西洋巡航轨道上的CFC-11、CFC-12和SF6的分布。他们将使用这些数据来识别北大西洋水团最近通风的核心，估计这些水团从它们的源头地区经过的时间，并使用经过时间信息估计耗氧率和在该计划上测量的选定微量元素的产生或分解速度。更广泛的影响：除了为GEOTRACES项目提供通风和过境时间的信息外，这次巡航收集的氟氯化碳和SF6数据还将扩大北大西洋的瞬变示踪剂数据库。这些数据将按照国家科学基金会的指导方针广泛传播给研究界。计划在2010-2012年期间进行几次前往北大西洋的CLIVAR邮轮，GEOTRACES邮轮将扩大对氟氯化碳和SF6的覆盖范围。这个北大西洋氟氯化碳和SF6浓度随时间演变的数据库用于研究地球气候和海洋在地球气候和全球二氧化碳循环中的作用。它用于验证海洋环流模型，并量化海洋中人为二氧化碳的吸收和储存。