Radiocarbon in Dissolved Organic Matter in Ocean Water

海水中溶解有机物中的放射性碳

• 批准号: 0961980
• 负责人: Ellen Druffel
• 金额: $ 57.09万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-02-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0961980&HistoricalAwards=false
• 关键词: Radiocarbon; Dissolved; Organic; Matter; Ocean

The average radiocarbon (14C) age of dissolved organic carbon (DOC) in the deep ocean ranges from 4000-6500 14C years. However, the data set used to estimate this range is based on only a few sites in the world ocean. For this reason, a scientist from the University of California, Irvine will participate in three CLIVAR Repeat Hydrography cruises to collect water samples from six detailed profiles in the Pacific and Atlantic Oceans for which there is no data (P6-along 32°S in the South Pacific, A10 along 30°S in the South Atlantic, and A20 along 50°W in the North Atlantic). Seawater samples will be analyzed by accelerator mass spectrometry to determine the 14C signatures of DOC. In addition, the black carbon from DOC will be isolated and analyzed for 14C and 13C signatures. With the data set, the scientist plans to test the following three hypotheses: (1) 14C of bulk DOC in the South Pacific Ocean is intermediate between values in the Southern Ocean and those in the North Pacific, and these 14C ages can be used to determine the timescale of DOC cycling in deep waters of the Pacific; (2) 14C levels in bulk DOC of the Atlantic Ocean are highest in the north (43°N), lower in the equatorial region (10°N) and lowest in the South Atlantic (30°S), and reflects the timescale of DOC cycling as deep water travels south in the western Atlantic; and (3) black carbon constitutes a significant amount of DOC in open ocean water, and its 14C age is greater than 20,000 14C years.The proponent will help high school teachers prepare science curricula for their classes and teaches a short course called "Radiocarbon in Ecology and Earth System Science" during the summer. She currently serves on the board for the Florida Center for Ocean Science Education Excellence and aids in the development of college level web-based educational classes. One graduate and two undergraduate students will be supported and trained as part of this project.

深海溶解有机碳（DOC）的平均放射性碳（14 C）年龄范围为4000-6500 14 C年。 然而，用于估计这一范围的数据集仅基于世界海洋中的几个地点。 为此，来自加州大学欧文分校的一名科学家将参加三次CLIVAR Repeat水文学巡航，从太平洋和大西洋六个没有数据的详细剖面收集水样（南太平洋P6-沿着32°S，南大西洋A10沿沿着30°S，北大西洋A20沿沿着50°W）。 将通过加速器质谱法分析海水样品，以确定DOC的14 C特征。 此外，将分离DOC中的黑碳并分析14 C和13 C特征。 科学家计划利用这一数据集检验以下三个假设：（1）南太平洋DOC的14 C年龄介于南太平洋和北太平洋之间，这些14 C年龄可以用来确定太平洋深层沃茨DOC循环的时间尺度;（2）大西洋DOC的14 C含量在北大西洋（43°N）最高，赤道区（10°N）较低，南大西洋（30°S）最低，反映了DOC在西大西洋深水区向南运动的时间尺度;（3）黑碳在开阔海水中构成了相当数量的DOC，其14 C年龄大于20，000 14 C年。倡议者将帮助高中教师为他们的班级准备科学课程，并在夏季教授一门名为“生态学和地球系统科学中的放射性碳”的短期课程。她目前在佛罗里达海洋科学教育卓越中心的董事会任职，并协助开发大学水平的基于网络的教育课程。一名研究生和两名本科生将作为该项目的一部分得到支持和培训。