Chromophoric DOM: An Ignored Photoactive Tracer of Geochemical Process

发色 DOM：一种被忽视的地球化学过程光活性示踪剂

• 批准号: 0241614
• 负责人: David Siegel
• 金额: $ 53.47万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0241614&HistoricalAwards=false
• 关键词: Chromophoric; DOM; Ignored; Photoactive; Tracer

ABSTRACTOCE-0241614Chromophoric dissolved organic material (CDOM), the colored fraction of the dissolved organic material (DOM) pool, is a highly dynamic property found throughout the open ocean. CDOM is an optical property; hence, its concentration can be quantified synoptically over large spatial scales using satellite-borne sensors or in situ from a host of autonomous platforms. Recent work demonstrates that net CDOM production is related to heterotrophic bacterial cycling processes while its losses are due to photobleaching. Vertical distributions of CDOM and in particular its surface signature are therefore regulated by how vertical mixing processes redistribute the basic processes of CDOM cycling. This suggests that CDOM may be an excellent tracer of upper ocean exchanges. In this study, researchers at the University of California - Santa Barbara will apply a process-level description of CDOM cycling to test its utility as a geochemical tracer. Specifically the research team will: (1) elucidate CDOM distributions over a range of oceanic regimes on several meridional sections of the CO2/CLIVAR Repeat Hydrography survey; (2) quantify and parameterize CDOM production & destruction processes with the goal of mathematically constraining the cycling of CDOM; (3) evaluate the utility of CDOM as an upper ocean age tracer by comparing with coincident tracer distributions from the Repeat Hydrography survey; and (4) develop a one-dimensional model of CDOM dynamics for use across a wide range of oceanic regimes with the goal of diagnosing mixed layer - thermocline exchanges.The proposed project has broad impacts beyond the world of academic ocean science. The three principal investigators on the project are active instructors, and results of this proposed work (and experiences gained) will be used in their course offerings at both the undergraduate and graduate levels. This research will support a dissertation of a graduate student at UCSB. All data will be freely available to all interested parties via a website at UCSB and the CO2/CLIVAR Repeat Hydrography Program. Finally, tf their scientific hypotheses prove correct, this research could lead to the remote estimation of water mass exchanges between the mixed layer and underlying waters from satellite orbit. A predictive understanding of these exchanges is critical for understanding the oceanic fate of anthropogenic compounds discharged to the atmosphere.

ABSTRACTOCE-0241614有色溶解有机物（CDOM），溶解的有色组分 有机物质（DOM）池是一个高度动态的财产发现整个开放的海洋。 CDOM是一种光学性质;因此，可以使用卫星传感器或通过许多自主平台在现场对大空间尺度上的浓度进行天气量化。 最近的研究表明，净CDOM的生产与异养细菌循环过程，而其损失是由于光漂白。 因此，垂直分布的CDOM，特别是其表面签名的调节垂直混合过程如何重新分配的CDOM循环的基本过程。 这表明CDOM可能是上层海洋交换的一个很好的示踪剂。 在这项研究中，加州大学-圣巴巴拉分校的研究人员将应用CDOM循环的过程级描述来测试其作为地球化学示踪剂的效用。 具体而言，研究小组将：（1）阐明CDOM在CO2/CLIVAR重复水文调查的几个纬向剖面上的一系列海洋状况中的分布;（2）量化和参数化CDOM的产生破坏过程，目的是在数学上限制CDOM的循环;（3）通过与符合CDOM的海洋年龄相比较，评估CDOM作为上层海洋年龄示踪剂的效用。 示踪剂分布的重复水文调查;和（4）开发一个一维模型的CDOM动力学，用于在广泛的海洋制度，诊断混合层-温跃层交换的目标。拟议的项目具有广泛的影响，超越了世界学术海洋科学。该项目的三名主要研究人员都是积极的教员，这项拟议工作的结果（和获得的经验）将用于本科生和研究生课程。 这项研究将支持UCSB研究生的论文。所有数据将通过UCSB网站和CO2/CLIVAR重复水文计划免费提供给所有感兴趣的各方。 最后，如果他们的科学假设被证明是正确的，这项研究可能导致从卫星轨道上远程估计混合层和下伏沃茨之间的水团交换。 对这些交换的预测性理解对于理解排放到大气中的人为化合物的海洋命运至关重要。