(EGB) Evaluating the Processes Governing Particle-Reactive Element Transport in an Arctic River System: Coupling Hydrology, Geochemical Tracers, and Hydrologic Models

9807590 Sayles我们提出了一个跨学科的方法来评估河流输运的沉积物和颗粒相关的污染物，适用于许多稀疏测量的河流为主的沿海系统。 为了克服数据的限制和覆盖大的空间尺度，我们建议联合使用地球化学，水动力学和水文数据集与高分辨率模型的传输和地球化学过程。 我们的目标是提供基本信息的途径，动力学和控制的运输和沉积环境，并探讨系统的敏感性，污染物负荷和积累。 这项研究的一个非常重要的方面是精心设计的方法，使用往往是最小的监测网络的河流系统与有限的实地观察。我们建议将研究重点放在流入北冰洋的四条最大河流之一鄂毕河上。 它在许多方面都是北极大型河流的代表，但在某种程度上是独一无二的，这大大增加了它对本研究的效用。 鄂毕河流域是前苏联大部分核武器生产和发展计划的所在地。 由于这些设施的排放，在过去的50年里，各种示踪剂被引入到已知点源的河流系统中，为研究污染物转移速率和机制以及这一大型北极河流系统内的基本沉积物输运和沉积提供了独特的机会。 我们将使用一个二维水动力学模型与沉积物输运和地球化学相互作用的子模型之间的河流数据集内插。 在统计意义上，我们将评估的粒子和相关示踪剂的命运是如何由地球化学，水文，河流的几何形状配置，和物理过程，必须响应于河流的几何形状，流量和泥沙输运的物理。 将通过为沉积物岩心编制详细的年表，建立从岩心中获得的地球化学数据、历史水文数据和模型之间的联系。 然后，这一年表将被用来与积累率和沉积物特性的变化在空间和时间上的多年变化的水文条件和模型predictions.Recently获得的数据从鄂毕河以上的汇合处与额尔齐斯提供了强有力的确认，在这个流域的研究效用。 这条河的沉积物含有独特的同位素标记，有效地“标记”了它的沉积物。 其中一个同位素比值240 Pu/239 Pu在过去50年中保持恒定，为识别下游混合物中的这些沉积物提供了一个标记。 第二示踪剂，237 Np，随时间强烈变化，高达一个数量级，提供了一个随时间变化的信号，用于估计运输和沉积速率。 这种独特的签名是实现这里提出的目标的理想选择。该提案已提交给EGB计划，并由以下机构共同资助：1. CTS（Arndt）和（Roco）2分部。第三节（Dudka）4.第四节（英语：Division of Women（Ledbetter））OCE分部-（Buesseler）

9807590SaylesWe propose an interdisciplinary approach for the evaluation of the riverine transport of sediments and particle-associated contaminants that is applicable to many sparsely measured river-dominated coastal systems. To overcome data restrictions and cover large spatial scales, we propose the joint use of geochemical, hydrodynamic, and hydrological data sets together with high-resolution models of transport and geochemical processes. Our objective is to provide basic information on the pathways, dynamics, and controls on transport and depositional environments, and to explore the sensitivity of the system to contaminant- loading and accumulation. A very important aspect of the study is the deliberate design of the approach to use the often-minimal monitoring network on river systems together with limited field observations. We propose to focus our study on the Ob River, one of the four largest rivers flowing into the Arctic Ocean. It is representative of large Arctic rivers in many respects, but is unique in a way that adds greatly to its utility for the present study. The Ob basin has been the site of the bulk of the nuclear weapons production and development program of the former Soviet Union. As a result of releases from thee facilities, a variety of tracers has been introduced, over the past 50 years, into the river system at known point-sources providing unique opportunities for studying pollutant transfer rates and mechanism, as well as basic sediment transport and deposition within this large arctic river system. We will use a two-dimensional hydrodynamic model with sediment-transport and geochemical interaction submodels to interpolate between river data sets. In a statistical sense, we will evaluate how the fate of the particles and associated tracers is governed by the geochemistry, the hydrology, the geometry of the river configuration, and the physical processes that must be responsive to the river geometry, flow, and the physics of sediment transport. The links between the geochemical data derived from the sediment cores, the historical hydrologic data, and the models will be established through developing detailed chronologies for the cores. This chronology then would be used to relate changes in accumulation rates and sediment characteristics in space and in time to multiyear changes in hydrologic conditions and model predictions.Recently obtained data from Ob above its confluence with the Irtysh provide strong confirmation of the utility of studies in this river basin. The sediments from this river contain uniques isotopic signatures that effectively "tag" its sediments. One isotopic ratio, 240Pu/239Pu, is ~constant over the past 50 years providing a label to identify these sediments in mixtures down stream. A second tracer, 237Np, varies strongly over times, by up to an order of magnitude, providing a time varying signal for use in estimating transport and deposition rates. Such unique signatures are ideal for meeting the goals proposed here. This proposal was submitted to the EGB Program and is being jointly funded by:1. Division of CTS (Arndt) and (Roco)2. Division of INT - (Dudka)3. Division of OPP - (Ledbetter)4. Division of OCE - (Buesseler)