Cycling of Dissolved Organic Matter in the Pacific and Indian Oceans Using Radiocarbon

使用放射性碳循环太平洋和印度洋中的溶解有机物

• 批准号: 1951073
• 负责人: Ellen Druffel
• 金额: $ 69.94万
• 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: 2020
• 资助国家: 美国
• 起止时间: 2020-02-15 至 2025-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1951073&HistoricalAwards=false
• 关键词: Cycling; Dissolved; Organic; Matter; Pacific

Controls on the Aging of Marine Dissolved Organic CarbonMost of the organic carbon in ocean water is in the dissolved form. Surprisingly, the age of this dissolved organic carbon is thousands of years old, even though it is thought to form during photosynthesis in the surface ocean. One explanation for the age of this carbon is the amount of time that it takes for carbon to circulate through the ocean. Investigators at the University of California Irvine (UCI) will investigate the aging of dissolved organic carbon in the Pacific, Southern and Indian oceans using C-14 isotopes. This work is important for knowing how carbon produced from human activities will be distributed on Earth in the future. This project will support the work of two graduate and two undergraduate students, providing hands-on experience that will prepare them for careers as scientists and educators. Both graduate students will be involved in a variety of educational activities. They will also help teach a short course on applications of C-14 in Ecology and Earth System Science for graduate students, technicians, postdocs and researchers during summer. UCI is a Hispanic-serving institution (27% of undergraduates identify as Hispanic), and 60% of students who attend UCI are first generation family representatives. This study will examine the concentration, isotopic (14C, 13C) and molecular composition of dissolved organic carbon (DOC) in depth profiles from the Pacific, Southern and Indian Oceans. This information will help to determine the main controls on DOC cycling in the world’s oceans. The project will test the hypothesis that circulation is the primary control on DOC cycling in the deepest water (3500 meters). The research will also investigate two alternative processes that could influence the age of DOC in deep water (2000-3000 meters): (1) dissolution of surface-derived particles and (2) input of ancient carbon from hydrothermal vents and flanks. Spectroscopic and spectrometric measurements designed to characterize a portion of the DOC will be performed on surface and deep water. Results will be incorporated into an inverse model of DOC cycling to determine the main processes controlling the DOC cycle in the ocean. DOC may serve as a sink for excess carbon dioxide produced from human activities and the size of the refractory DOC pool in the ocean could increase as circulation slows. Measuring the 14C age of DOC in the surface and deep ocean is important for understanding how the global carbon cycle will change as the Earth's climate shifts.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.

对海水中有机碳溶解有机碳的衰老的控制是溶解的形式。令人惊讶的是，这种溶解的有机碳的年龄已有数千年的历史，即使人们认为在地面海洋的光合作用过程中形成。关于该碳年龄的一种解释是碳通过海洋循环所需的时间。加州大学尔湾分校（UCI）的调查人员将使用C-14同位素调查太平洋，南部和印度洋溶解有机碳的老化。这项工作对于了解将来将在地球上分发从人类活动中产生的碳生产的碳很重要。该项目将支持两名研究生和两名本科生的工作，提供动手经验，为他们作为科学家和教育工作者的职业做好准备。两位研究生将参与各种教育活动。他们还将在夏季为研究生，技术，博士后和研究人员提供有关C-14在生态和地球系统科学中的应用的简短课程。 UCI是西班牙裔服务机构（27％的本科生认为是西班牙裔），而参加UCI的学生中有60％是第一代家庭代表。这项研究将在太平洋，南部和印度洋的深度剖面中检查溶解有机碳（DOC）的浓度，同位素（14C，13C）和分子组成。这些信息将有助于确定有关世界海洋中DOC骑自行车的主要控制。该项目将检验以下假设：循环是最深水（3500米）中DOC骑自行车的主要控制。该研究还将研究两个可能影响深水中DOC时代的替代过程（2000-3000米）：（1）溶解表面衍生的颗粒，（2）（2）对古代碳输入从热液通风孔和侧面中输入。旨在表征DOC的一部分的光谱和光谱测量值将在表面和深水上进行。结果将纳入DOC循环的反向模型，以确定控制海洋DOC周期的主要过程。 DOC可以用作人类活动产生的过量二氧化碳的水槽，随着循环速度的速度，海洋难治性DOC池的大小可能会增加。在地面和深海中测量DOC的14c年龄对于理解地球气候变化时全球碳周期将如何变化很重要。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子和更广泛的影响评估标准来通过评估来表现出珍贵的支持。