Radiocarbon Studies of Dissolved and Particulate Organic Carbon in the Eastern North Pacific and Amazon Plume Regions

有机碳循环将在两个开阔的海洋地点进行研究，这反映了来自海洋和陆地来源的碳的潜在差异。碳同位素、溶解有机碳和颗粒有机碳的研究将在东北太平洋的“M”站和大西洋的亚马逊河羽流区域进行。DOC浓度的控制和。还将评估天然微生物组合的14C值。不同碳库之间的关系，包括沉积有机碳（SOC），将在“M”站的高和低初级生产力时期以及亚马逊河羽流/大西洋水域的样带中进行评估。以下问题将被解决：(1)碳的种类和。14C梯度是开放海洋中季节性碳通量率的函数？(2)陆源碳物种对开放海洋的贡献是什么？(3)同位素活度是否根据颗粒大小和/或有机组成进行分馏？(4)总DOC池中潜在不稳定和真正难熔的比例是多少？每个分数的14C签名？

The organic carbon cycle will be studied at two open ocean sites which reflect potential differences in carbon derived from marine and terrestrial sources. Studies of carbon isotopes and dissolved and particulate organic carbon will be conducted at Station "M" in the Northeast Pacific Ocean and in the Amazon River plume region of the Atlantic Ocean. The control of DOC concentrations and . 14C values by natural microbial assemblages will also be evaluated. Relationships between the different carbon pools, including sedimentary organic carbon (SOC), will be assessed at Station "M" during periods of high and low primary productivity and in a transect of Amazon River plume/Atlantic Ocean waters. The following questions will be addressed: (1) Are carbon species and . 14C gradients a function of seasonal carbon flux rates in the open ocean? (2) What is the contribution of terrestrially derived carbon species to the open ocean? (3) Are isotopes activities fractionated with respect to particle size and/or organic composition? (4) What fraction of the total DOC pool is potentially labile and truly refractory, and what are the . 14C signatures of each fraction?