Geochemical Tracers in the Northwater Polynya

这项建议寻求支持主要调查员参与由加拿大组织的多调查员国际北水波利尼亚方案。这个更大的项目将检验波尼亚形成的假说，这一提议将提供对了解当今生态系统动态及其与波尼亚大小和形成过程的关系十分重要的地球化学示踪测量。具体地说，地球化学示踪工作涉及两类与北水Polynya有关的过程：1)颗粒有机碳(POC)的下沉通量，2)净群落生产和碳循环。POC的下沉通量将根据天然U-238系列放射性核素Th-237的水柱分布来量化。利用水体中营养盐、氧和溶解无机碳(DIC)的分布来推算北水生态系统的净生物生产量。将测量溶解有机碳，以检查DOC和POC池之间的分配。主要调查员应邀参加了1998年加拿大赞助的波利尼亚游轮。拟议的抽样计划将涉及化探示踪剂的空间和时间变异性。

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.