Selecting and Applying an Inverse Method to Infer Particle Dynamics from GEOTRACES Data

选择并应用反演方法从 GEOTRACES 数据推断粒子动力学

• 批准号: 1232578
• 负责人: Olivier Marchal
• 金额: $ 52.94万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1232578&HistoricalAwards=false
• 关键词: Selecting; Applying; Inverse; Method; Infer

Processes affecting ocean particles have important consequences for the marine biogeochemical cycles of trace elements; however, our present understanding of these processes is incomplete, as shown by the very large uncertainties (spanning orders of magnitude) of current estimates of particle cycling rates in the ocean. The extensive trace element dataset being generated as part of the GEOTRACES program provides an opportunity to enhance our knowledge of particle processes in a variety of oceanic environments. A scientist from Woods Hole Oceanographic Institution plans to determine the adequacy of different inverse methods to constrain particle processes such as solid-solution exchange and particle processes in the water column from measurements of thorium isotope activity, particle composition, and particle concentration in different size fractions. To attain this goal, the researcher would first assess the adequacy of different inverse methods to infer, from such an eclectic dataset, rate constants of sorption reactions (adsorption and desorption) and particle dynamics (aggregation, disaggregation, sinking, and remineralization). The second step would involve applying the selected method to estimate these constants and their uncertainties at the "superstations" of the GEOTRACES North Atlantic Zonal Section. Once the model is in place, the scientist would test the hypotheses that the rate constants varied (1) vertically within the mesopelagic layer and the deeper layers at these stations and (2) horizontally across the diverse environments sampled along the section.Broader Impacts: The software to be developed would be archived with the Biological and Chemical Oceanography Data Management Office with instructions so other scientist can use it. One graduate student would be trained on the use of inverse methods in data analyses.

影响海洋颗粒的过程对微量元素的海洋生物地球化学循环有重要影响;然而，我们目前对这些过程的理解是不完整的，如目前对海洋颗粒循环速率的估计存在很大的不确定性（跨越数量级）所示。作为GEOTRACES计划的一部分，正在生成的广泛的微量元素数据集提供了一个机会，以提高我们对各种海洋环境中粒子过程的了解。 来自伍兹霍尔海洋研究所的一位科学家计划通过测量钍同位素活性、颗粒成分和不同粒径组分的颗粒浓度，确定不同的逆方法是否足以限制颗粒过程，如水柱中的固溶体交换和颗粒过程。为了实现这一目标，研究人员将首先评估不同的逆方法的充分性，从这样一个折衷的数据集，吸附反应（吸附和解吸）和颗粒动力学（聚集，解聚，下沉和再矿化）的速率常数推断。第二步将涉及应用选定的方法来估计GEOTRACES北大西洋带状部分的“超级站”的这些常数及其不确定性。一旦建立了模型，科学家将检验以下假设：（1）在这些站点的中层和深层内，速率常数在垂直方向上是变化的;（2）在沿剖面沿着取样的不同环境中，速率常数在水平方向上是变化的。将开发的软件将在生物和化学海洋学数据管理办公室存档，并附有说明，以便其他科学家可以使用。一名研究生将接受关于在数据分析中使用逆向方法的培训。