Geochemical Tracers in the Northwater Polynya

本建议寻求支持主要研究人员参加由加拿大组织的多研究人员国际北水波利亚方案。更大的项目将测试多冰湖形成的假设，该提案将提供地球化学示踪测量，这对于了解当今生态系统动力学及其与多冰湖大小和形成过程的关系非常重要。具体而言，地球化学示踪剂工作涉及北水多冰带的两类过程：1)颗粒有机碳（POC）的下沉通量，以及2)净群落生产和碳循环。根据天然U-238系列放射性核素Th-237的水柱分布，量化POC的沉降通量。水体中营养物质、氧和溶解无机碳（DIC）的分布将被用来推断北水生态系统的净生物产量。将测量溶解有机碳，以检查DOC和POC池之间的划分。主要研究人员已被邀请参加1998年由加拿大赞助的到玻里尼亚的巡航。地球化学示踪剂的时空变化将在拟议的抽样方案中加以解决。

This proposal seeks support for the principal investigators' participation in the multi-investigator, international North Water Polynya Program organized by Canada. The larger project will test hypotheses for the formation of the polynya, and this proposal will supply Geochemical tracer measurements that are important in gaining an understanding of the present-day ecosystem dynamics and their relations to polynya size and formation processes. Specifically, the Geochemical tracer work addresses two classes of processes operating with the North Water polynya: 1) the sinking flux of particulate organic carbon (POC), and 2) net community production and carbon cycling. The sinking flux of POC will be quantified based on the water column distributions of the natural U-238 series radionuclide Th-237. The distribution of nutrients, oxygen and dissolved inorganic carbon (DIC) in the water column will be used to deduce the net biological production of the North Water ecosystem. Dissolved organic carbon will be measured to examine the partitioning between the DOC and POC pools. The principal investigators have been invited to participate in the 1998 Canadian-sponsored cruise to the polynya. Both spatial and temporal variability in the Geochemical tracers will be addressed in the proposed sampling scheme.