Organic Geochemical Studies in the Southern Ocean

9531759 Wakeham该研究项目是美国联合全球海洋通量研究（JGOFS）南大洋计划的一部分，旨在（1）更好地了解南大洋的有机和无机碳通量，（2）确定调节这些通量的大小和变化的物理，生态和生物地球化学因素和过程，（3）将这些通量置于当代全球碳循环的背景下。这项工作是南大洋实验中合作的44个项目之一，南大洋实验是一项为期三年的南极极地锋区南部的努力，旨在跟踪碳通过其有机和无机途径从空气-海洋界面通过整个水柱进入底部沉积物的流动。实验将使用RVI B Nathaniel B。帕默和汤普森号这一部分涉及对南大洋水柱和表层沉积物中有机物循环的合作研究。这项工作的主要目标是：（1）确定南大洋内有机物质的组成和通量如何随区域和季节变化，（2）将这些变化与间断有机输入及其硅质基质的生物处理联系起来，（3）追踪浮游生物残留物向下通过水柱进入下层沉积物的成岩命运，特别强调反映基质质量（新鲜度）的生物化学趋势;（4）通过对大量收集器和沉积物样品进行碳-13分析，全面说明所有降解阶段的总有机物。船上的工作包括收集悬浮和降雨颗粒材料的水柱和从下面的沉积物在几个地点沿着拟议的研究样带。悬浮颗粒将通过浮游生物网和地表水的高容量过滤来收集。沉降颗粒将用四个一组的模块式沉积物收集器收集。个别捕集器的设计将有选择地收集下沉的颗粒，并拒绝游泳浮游动物，而不会损失样品或生物杀灭剂。每个阵列上的四个陷阱中的两个将安装有12管二次采样转盘，以研究短期变化。将分析收集到的捕集器和沉积物芯样的基本生物化学组成部分，如碳水化合物、氨基酸、脂类、木质素和色素。这些物质构成了上层水柱中产生的大部分有机物质，也是沉积物中埋藏物质的重要组成部分。在分子一级，它们可以提供关于有机物质来源及其在深度的分解情况以及生物物质转移到沉积物的途径的明确信息。这些数据将与以前的联合全球海洋观测系统实验中获得的信息相结合，以产生海洋颗粒物质有机化学的全球图像。***

9531759 Wakeham This research project is part of the US Joint Global Ocean Flux Study (JGOFS) Southern Ocean Program aimed at (1) a better understanding of the fluxes of carbon, both organic and inorganic, in the Southern Ocean, (2) identifying the physical, ecological and biogeochemical factors and processes which regulate the magnitude and variability of these fluxes, and (3) placing these fluxes into the context of the contemporary global carbon cycle. This work is one of forty-four projects that are collaborating in the Southern Ocean Experiment, a three-year effort south of the Antarctic Polar Frontal Zone to track the flow of carbon through its organic and inorganic pathways from the air-ocean interface through the entire water column into the bottom sediment. The experiment will make use of the RVIB Nathaniel B. Palmer and the R/V Thompson. This component concerns a cooperative study of organic matter cycling in the water column and in the surficial sediments of the Southern Ocean. The main goals of the effort are: (1) to determine how the composition and fluxes of organic material vary regionally and seasonally within the Southern Ocean, (2) to relate these variations to biological processing of the punctuated organic input and its siliceous matrix, (3) to follow the downward diagenetic fate of planktonic remains through the water column and into the underlying sediments, with special emphasis on biochemical trends reflecting substrate quality (freshness), and (4) to holistically account for total organic matter at all stages of degradation by carbon-13 analysis of bulk trap and sediment samples. The shipboard work involves collecting suspended and raining particulate material within the water column and from the underlying sediment at several sites along the proposed study transect. Suspended particles will be collected both by plankton net tows and high volume filtration of surface water. Sinking particles will be collected with modular sediment traps deployed in arrays of four. Individual traps will be designed to selectively collect sinking particles and reject swimming zooplankton without loss of sample or biocide. Two of the four traps on each array will be fitted with 12-tube subsampling carousels to study shorter term variations. The collected trap and sediment core samples will be analyzed for their basic biochemical building blocks, such as carbohydrates, amino acids, lipids, lignins, and pigments. These make up the bulk of the organic matter produced in the upper water column and are an important fraction of the material buried in the sediment. At the molecular level they can provide unequivocal information on the sources of organic matter and its decomposition at depth, and on the pathways by which biogenic material is transferred to the sediment. These data will be combined with information obtained during prior JGOFS experiments to produce a global picture of the organic chemistry of particulate matter in the ocean. ***