234Th as a Tracer of Particulate C and N Export in the Equatorial Pacific

该项目的目标是利用第234次数据量化赤道太平洋真光带底部有机碳和氮的颗粒通量。1992年春季和秋季第234：238U不平衡的测量将被用来量化赤道南北横断面在西经170度到西经110度之间的第234次颗粒物通量。通量数据将与有机C/234和N/234关于粒子级分物质的测量相结合，为了计算有机碳和氮的颗粒通量，利用234TH的船上伽马能谱分析，通量数据将接近实时。使用就地抽水系统，所有样本的采集将独立于其他采样活动。有了这个数据集，赤道太平洋在全球碳收支中向海洋内部移走碳和相关营养物质(新的生产量)的作用将能够被量化。此外，季节和空间覆盖将使新产品作为DOM出口而不是沉淀颗粒的程度得到解决，负责确定碳出口效率与上层海洋回收效率的过程将得到更好的理解。

The goal of this project is to use 234Th data to quantify the particulate flux of organic C and N at the base of the euphotic zone in the equatorial Pacific. Measurements of 234Th: 238U disequilibria in the spring and fall of 1992 will be used to quantify the particulate 234Th flux in north to south transects across the equator between 170 degrees W to 110 degrees W. The flux data will be combined with measurements of organic C/234Th and N/234Th ratios on size-fractionated particulate matter, to calculate the particulate flux of organic C and N. By taking advantage of shipboard gamma spectrometric analyses of 234Th, the flux data will be available in close-to-real time. Using an in- situ pumping system, all samples will be collected independent of other sampling activities. With this data set the equatorial Pacific's role in the global C budget for the removal of C and associated nutrients to the ocean's interior (new production) will be able to be quantified. In addition, the seasonal and spatial coverage will allow the extent to which new production is being exported as DOM rather than settling particles to be resolved, and the processes responsible for determining the efficiency of C export vs. recycling in the upper oceans will be better understood.