Evaluating the Effects of High Particulate Fluxes on Chemical Processes Occurring at the Amazon River/Ocean Boundary (Renewal)

这项建议是对现有补助金的更新， "评估亚马逊河流域高颗粒通量的影响 河流/海洋边界，"这是AmasSeds（一个多- 亚马逊大陆架沉积物研究项目。 三个研究 亚马逊大陆架巡航（1989年8月; 1990年2月; 5月） 1991年11月，顺利完成。 时间 一系列的方法来理解化学，物理， 在亚马逊河/海洋边界活跃的地质作用 使研究人员能够解决变量的影响， 河流流量，潮汐再悬浮，局部风应力， 海岸流强度对颗粒相关过程的影响。 本建议书所述的具体研究课题包括： 1)评价悬浮泥沙浓度对 营养物质和碳的生物吸收和再生; 2） 镭同位素从粒子中释放到水柱中 及其在跟踪海床/水柱方面的用途 交换过程; 3）清除颗粒活性元素 大陆架沃茨的铀循环; 河流/海洋混合; 5）追踪生物和物理 基于碳分布的亚马逊大陆架上的过程 和稳定同位素数据。 放射性示踪剂的测量 水柱和海床使研究人员能够描述 许多这些过程在各种时间尺度上（范围从 几天到几百年）。 该提案要求支持两个 额外的研究年数，将用于完成数据 分析，处理单个数据集，模拟初始结果， 并将实地测量结果与其他研究小组 参加这个项目。

This proposal is a renewal for the existing grant entitled "Evaluating the Effects of High Particulate Fluxes at the Amazon River/Ocean Boundary," which is part of the AmasSeds (A Multi- Disciplinary Amazon Shelf SEDiment Study) Project. Three research cruises to the Amazon shelf (August 1989; February, 1990; and May 1990; and November, 1991) have been completed successfully. Time series approach to understanding the chemical, physical, and geological processes active at the Amazon River/ocean boundary enables the investigators to resolve the variable influences of river discharge, tidal resuspension, local wind stress, and the intensity of coastal currents on particle-associated processes. The specific topics of research described in this proposal include: 1) evaluating the effects of suspended sediment concentration on the biological uptake and regeneration of nutrients and carbon; 2) the release of radium isotopes to the water column from particles and sediments and their use in tracking seabed/water column exchange processes; 3) scavenging of particle-reactive elements from continental shelf waters; 4) uranium cycling during river/ocean mixing; and 5) tracing biological and physical processes on the Amazon shelf based on the distribution of carbon and stable isotopic data. Measurements of radioactive tracers in the water column and seabed enable investigators to characterize many of these processes on a variety of time scales (ranging from days to hundreds of years). This proposal requests support for two additional years of research, which will be used to complete data analyses, work up individual data sets, model the initial results, and integrate the field measurements with the other research groups taking part in the project.